Fusion proteins comprising a GLP-1 receptor agonist and a myostatin pathway inhibitor

Abstract

Fusion molecules comprising an obesity-related peptide moiety, fused to a myostatin pathway inhibitor moiety are disclosed. Also disclosed are nucleic acids and expression vectors encoding, compositions comprising, and methods of using, the fusion molecules.

Description

[0001] Fusion Molecules

[0002] Technical Field

[0003] The present disclosure relates to the fields of molecular biology and methods of medical treatment and prophylaxis. In particular, the present disclosure relates to fusion molecules for use in such methods.

[0004] Background

[0005] The prevalence of overweight and obesity is a significant global health issue. According to the World Health Organization (WHO), over 2.5 billion adults were overweight in 2022, with more than 650 million classified as obese. Additionally, in 2022, 37 million children under the age of 5 and over 390 million children and adolescents aged 5-19 were overweight or obese. These conditions contribute to numerous health problems, including cardiovascular diseases, type 2 diabetes, musculoskeletal disorders, and certain cancers. The economic burden is substantial, with the estimated annual medical cost of obesity in the United States alone nearly $173 billion in 2019 (Ward et al., PLoS One. (2021) 16(3):e0247307).

[0006] Several GLP-1 receptor agonists have been developed for the treatment of obesity. These agents activate the GLP-1 receptor and promote weight-loss though delayed gastric emptying, appetite suppression and increased satiety of the subject. However, these agents often result in side effects like gastrointestinal issues and pancreatitis. GLP-1 receptor agonists and their side effects are reviewed in Wang et al., Front Endocrinol. (2023) 1 (14):1085799, which is hereby incorporated by reference in its entirety.

[0007] Moreover, clinical trials have determined that GLP-1 receptor agonist-induced weight loss is often accompanied with significant loss (e.g. 20-40 %) of muscle mass (also called “muscle atrophy”). This can negatively impact the living quality and life expectancy of patient populations, especially elderly patients. In addition, a sustained weight loss regimen should not rely only on temporally reduction of calories intake but also retaining / increase of the proportion of lean mass to increase the basic metabolic rate of the subject.

[0008] Thus, there is a critical need for better weight management therapies that minimize side effects and avoid muscle loss.

[0009] Recently, Versanis / Eli Lilly proposed the combined usage of two separate drugs, a GLP-1 receptor agonist and Bimagrumab (an antibody targeting both the activin receptor HA and I IB, blocking the myostatin signaling pathway), to achieve weight loss while preventing muscle atrophy (Clinical trial NCT05616013). Furthermore, the combination treatment of bimagrumab and semaglutide led to body weight reduction in obese mice with minimal lean mass loss despite reduced food intake (Nunn et al., Mol Metab. (2024) 80:101880).

[0010] Summary

[0011] In a first aspect, the present disclosure provides a fusion molecule comprising an obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety. In some embodiments, the obesity related peptide moiety is a Glucagon-like peptide 1 (GLP-1) receptor agonist moiety.

[0012] In some embodiments, the GLP-1 receptor agonist moiety is, or comprises, a peptide, polypeptide or polypeptide complex; and / or the myostatin pathway inhibitor moiety is a peptide, polypeptide or polypeptide complex.

[0013] In some embodiments, the obesity-related peptide moiety is a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist.

[0014] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule. In some embodiments, the antigen-binding molecule specifically binds myostatin, ActRIIA, ActRIIB, ActRIIA and ActRIIB or Activin A.

[0015] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that binds to a myostatin pathway protein. In some embodiments, the myostatin pathway protein is ActRIIA, ActRIIB, ActRIIA and ActRIIB or Activin A.

[0016] In some embodiments, the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is directly fused to the myostatin pathway inhibitor moiety.

[0017] In some embodiments, the n obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the myostatin pathway inhibitor moiety via a linker, optionally a cleavable linker. In some embodiments, the linker is a protease-cleavable linker.

[0018] In some embodiments, the fusion molecule further comprises a muscle-preserving moiety. In some embodiments, the muscle-preserving moiety is, or comprises, a myostatin pathway inhibitor.

[0019] In some embodiments, the muscle-preserving moiety is an scFv. In some embodiments, the musclepreserving moiety is a VHH.

[0020] In some embodiments, the muscle-preserving moiety is fused to the C-terminus of the myostatin pathway inhibitor moiety. In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antibody that binds to a myostatin pathway protein, wherein the muscle-preserving moiety is fused to the C-terminus of a constituent polypeptide of the antibody that binds to a myostatin pathway protein.

[0021] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain and an antibody light chain, and wherein the fusion molecule is a polypeptide complex comprising: (i) a first polypeptide comprising an antibody heavy chain and a muscle-preserving moiety, wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain; and

[0022] (ii) a second polypeptide comprising the antibody light chain.

[0023] In some embodiments, the fusion molecule further comprises a first obesity-related peptide moiety and a second obesity-related peptide moiety.

[0024] In some embodiments, the fusion molecule comprises, or consists of: i) a Glucagon-like peptide 1 (GLP-1) receptor agonist moiety; ii) an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist; and iii) a myostatin pathway inhibitor moiety.

[0025] In some embodiments, the obesity-related peptide moiety is fused to the myostatin pathway inhibitor moiety via a linker, optionally a protease-cleavable linker.

[0026] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain, and the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain.

[0027] In some embodiments, the C-terminus of the obesity-related peptide moiety (e.g. GLP-1 receptor agonist peptide) is fused to the myostatin pathway inhibitor peptide or polypeptide. In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, a peptide, polypeptide or polypeptide complex, wherein the C-terminus of the GLP-1 receptor agonist moiety is fused to the myostatin pathway inhibitor moiety peptide, polypeptide or to a constituent polypeptide of the myostatin pathway inhibitor moiety polypeptide complex.

[0028] In some embodiments, the obesity-related peptide moiety (e.g. GLP-1 receptor agonist peptide) is fused to the N-terminus of the myostatin pathway inhibitor peptide or polypeptide. In some embodiments the myostatin pathway inhibitor moiety is, or comprises, a peptide, polypeptide or polypeptide complex, wherein the GLP-1 receptor agonist peptide is fused to the N-terminus of the myostatin pathway inhibitor moiety peptide, polypeptide, or to the N-terminus of a constituent polypeptide of the myostatin pathway inhibitor moiety polypeptide complex.

[0029] In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule comprising an antibody heavy chain, and wherein the obesity-related peptide moiety (e.g. GLP- 1 receptor agonist moiety) is fused to the N-terminus of the antibody heavy chain.

[0030] In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule comprising an antibody light chain, and wherein the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the N-terminus of the antibody light chain. In some embodiments, the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the C-terminus of the myostatin pathway inhibitor.

[0031] In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule comprising an antibody heavy chain, wherein the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the C-terminus of the antibody heavy chain.

[0032] In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule comprising an antibody light chain, wherein the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the C-terminus of the antibody light chain.

[0033] In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule comprising an antibody light chain, wherein the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the C-terminus of the antibody light chain.

[0034] In some embodiments, the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is chemically conjugated to the myostatin pathway inhibitor moiety.

[0035] In some embodiments, the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is chemically conjugated to the myostatin pathway inhibitor moiety via cysteine-based conjugation.

[0036] In some embodiments, the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is chemically conjugated to the myostatin pathway inhibitor moiety via a chemical linker comprising a maleimide or bromo-acetamide group.

[0037] In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antibody, wherein the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is chemically conjugated to the CH2 region of the antibody.

[0038] In some embodiments, the GLP-1 receptor agonist comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity to SEQ ID NO: 2.

[0039] In some embodiments, the GLP-1 receptor agonist moiety is, or comprises, Semaglutide, Dulaglutide, Tirzepatide, AMG-133, Survodutide or Retatrutide.

[0040] In some embodiments, the myostatin pathway inhibitor moiety is an inhibitor of myostatin, ActRIIA, ActRIIB, ActRIIA and ActRIIB or Activin A.

[0041] In some embodiments, the myostatin pathway inhibitor moiety is Apitegromab, GYM329, Taldefgrobep alfa, KER-065, Trevogrumab, Garetosmab, Bimagrumab (BYM338), and BIO101 (20-hydroxyecdysone). In a further aspect, the present disclosure provides a conjugate comprising (i) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antigen binding molecule; (ii) a chemical linker comprising a maleimide or bromo-acetamide group; and (iii) an obesity-related peptide moiety (e.g. GLP-1 receptor agonist peptide moiety).

[0042] In a further aspect, the present disclosure provides a polynucleotide, or plurality of polynucleotides, encoding a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor.

[0043] In some embodiments, the polynucleotide encodes from 5’ to 3’:

[0044] (i) an obesity-related peptide moiety (e.g. GLP-1 receptor agonist); and

[0045] (ii) a myostatin pathway inhibitor.

[0046] In a further aspect, the present disclosure provides a pharmaceutical composition comprising a fusion molecule or conjugate comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety (e.g. according to any of the previous aspects), and a pharmaceutically acceptable carrier.

[0047] In a further aspect, the present disclosure provides a method of treating or preventing a disease or condition, comprising administering a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety, a polynucleotide or plurality of polynucleotides encoding a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety, or a pharmaceutical composition comprising a fusion molecule or conjugate according to any of the previous aspects, to a patient in need thereof.

[0048] In a further aspect, the present disclosure provides a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety, a polynucleotide or plurality of polynucleotides encoding a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety, or a pharmaceutical composition comprising a fusion molecule or conjugate according to any of the previous aspects, for use in a method of treating or preventing a disease or condition.

[0049] In some embodiments, the disease or condition is obesity, insulin dependent diabetes mellitus or noninsulin dependent diabetes mellitus.

[0050] In a further aspect, the present disclosure provides a method of treating obesity, comprising administering a fusion molecule comprising (i) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide or polypeptide; and / or (ii) an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist, fused to (iii) a myostatin pathway inhibitor moiety, wherein the a myostatin pathway inhibitor is antigenbinding molecule.

[0051] In a further aspect, the present disclosure provides a fusion molecule comprising (i) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide or polypeptide; and / or (ii) an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist, fused to (iii) a myostatin pathway inhibitor moiety; wherein the a myostatin pathway inhibitor is an antigen-binding molecule; for use in a method of treating obesity.

[0052] Description

[0053] Fusion Molecules

[0054] The present invention relates to fusion molecules comprising an obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety.

[0055] This invention addresses unmet clinical needs by developing the next generation of weight management therapies. Fusing obesity-related peptide moieties (e.g. GLP-1 receptor agonists) with molecules that inhibit the myostatin pathway achieves the effects of weight reduction while preserving lean muscle mass. Moreover, components of the myostatin pathway are primarily expressed in muscles, the pancreas, and the brain. This means the fusion molecules can target these key areas, reducing peripheral circulation concentration and significantly decreasing gastrointestinal side effects while increasing the half-life of the obesity-related peptide moiety.

[0056] In all embodiments described herein, the fusion molecule may be a fusion protein. For example, a GLP-1 receptor agonist peptide or polypeptide, fused to a myostatin pathway inhibitor peptide or polypeptide. In some embodiments the fusion molecule is, or comprises, a polypeptide complex.

[0057] Obesity-Related Peptides

[0058] Disclosed herein are fusion molecules comprising an obesity-related peptide moiety, fused to a myostatin pathway inhibitor moiety.

[0059] GLP-1 receptor agonists

[0060] In some embodiments, the obesity-related peptide moiety is a GLP-1 receptor agonist. Accordingly, disclosed herein in some embodiments are fusion molecules comprising a GLP-1 receptor agonist moiety fused to a myostatin pathway inhibitor moiety. Glucagon-like peptide 1 (GLP-1) and gastric inhibitory peptide (GIP), also known as: glucose-dependent insulinotropic polypeptide, belong to a group of metabolic hormones called incretins which are produced in the gut in response to food, stimulate insulin secretion in response to nutrient intake, and result in a decrease in blood glucose levels. GLP-1 (7-37) is a truncated, bioactive form of of human GLP-1 . The amino acid sequence of GLP-1 (7- 37) (referred to herein as “native GLP-1”) is set out in SEQ ID NO: 1 . GLP-1 asserts its effects through binding to the GLP-1 receptor (GLP1 R), expression of which is enriched in the brain, digestive tract, gastrointestinal tract, pancreas and muscle tissues. GLP1 R binding in the presence of elevated glucose concentrations leads to stimulation of insulin secretion. GLP-1 decreases gastrointestinal mobility (i.e. delays gastric emptying), promotes satiety and has been shown to increase resting energy expenditure. Furthermore, exogenous treatment of native GLP-1 can restore the insulin secretory response in type 2 diabetes patients. These effects make GLP-1 an attractive therapeutic target. However, therapeutic use of native GLP-1 is limited by a short half-life (approximately 2 minutes) due to rapid degradation by the enzyme dipeptidyl peptidase 4 (DPP-4) (see Nauck et al., J Clin Invest. (1993) 91 (1):301 -7 and Deacon et al., Diabetes. (1995) 44(9):1126-31 which are both hereby incorporated by reference in their entirety).

[0061] “GLP-1 receptor agonists” as described herein are also known as “GLP-1 RAs”, “GLP-1 s”, “GLP-1 analogs”, “GLP-1 peptides” or “incretin mimetics”. It will be appreciated that the term ‘moiety’ as used herein is not intended to be limiting. By way of illustration, the essential element of a GLP-1 receptor agonist moiety as described herein, is a GLP-1 receptor agonist as described herein.

[0062] In some embodiments, a GLP-1 receptor agonist moiety as described herein is a GLP-1 receptor agonist peptide. As used herein, a ‘peptide’ refers to a chain of two or more amino acid monomers linked by peptide bonds. A peptide typically has a length in the region of about 2 to 50 amino acids. GLP-1 receptor agonists mimic the action of native GLP-1 and have been shown to be effective in promoting weight-loss. Like native GLP-1 , the mechanism of GLP-1 receptor agonists in inducing weight loss mainly acts through delayed gastric emptying, appetite suppression and increased satiety of the subject, hence leading to a reduced calorie intake and a net calorie deficit that promotes weight loss.

[0063] In some embodiments, the GLP-1 receptor agonist moiety is, or comprises, native GLP-1 , or a fragment thereof. Accordingly, in some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 1 . In some embodiments, the GLP-1 receptor agonist moiety is a GLP-1 receptor agonist peptide having a length of 31 amino acids and having 100% amino acid sequence identity to SEQ ID NO: 1 .

[0064] In some embodiments, the GLP-1 receptor agonist moiety is, or comprises, a fragment of native GLP-1 . In other words, in some embodiments the GLP-1 receptor agonist comprises, or consists of, an amino acid sequence having a length of 25-31 amino acids e.g. a fragment of 25, 26, 27, 28, 29, 30 or 31 amino acids of SEQ ID NO: 1. In some embodiments, the GLP-1 receptor agonist moiety is, or comprises, a GLP-1 receptor agonist peptide having a length of 22-31 amino acids and having at least 70% amino acid sequence identity to SEQ ID NO: 1 .

[0065] Because of the short half-life of native GLP-1 , new GLP-1 receptor agonists which are resistant to degradation by DPP-4 have been developed. The GLP-1 receptor agonist moiety of the present disclosure may be a peptide comprising amino acid substitutions relative to native GLP to reduce DPP4 protease cleavage and improve in vivo half-life. For example, the GLP-1 receptor agonist moiety of the present disclosure may be a peptide having one or more substitutions relative to SEQ ID NO: 1 selected from Ala8Amino-isobuthyric acid, Ala8Gly, Gly22Glu, Lys34Arg, and Arg36Gly. Modifications are described herein using amino acid numbering relative to the non-truncated form of human GLP-1 , e.g. Ala8Gly refers to a modification of the second amino acid of GLP-1 (7-37) (SEQ ID NO: 1). In some embodiments, the GLP-1 receptor agonist moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity to SEQ ID NO: 1 and having one or more substitutions selected from Ala8Amino-isobuthyric acid, Ala8Gly, Gly22Glu, Lys34Arg, Arg36Gly.

[0066] In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence comprising amino acid substitutions Ala8Gly, Gly22Glu and Arg36Gly relative to native GLP. Accordingly, in some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 2. In some embodiments the GLP-1 receptor agonist moiety comprises, or consists of, an amino acid sequence having a length of 25- 31 amino acids e.g. a fragment of 25, 26, 27, 28, 29, 30 or 31 amino acids of SEQ ID NO: 2. In some embodiments, the GLP-1 receptor agonist moiety is, or comprises, a GLP-1 receptor agonist peptide having a length of 31 amino acids and having 100% amino acid sequence identity to SEQ ID NO: 2.

[0067] Fatty acid conjugation can also be used to improve in vivo half-life of GLP-1 receptor agonist peptides because of the high binding affinity of human serum albumin for fatty acids (e.g. as described in Li et al. Sci Rep. (2015) 11 ;5:18039 which is hereby incorporated by reference in its entirety). Accordingly, in some embodiments, the GLP-1 receptor agonist moiety comprises a fatty acid conjugation (also called lipidation).

[0068] GLP-1 receptor agonists can be identified by those skilled in the art. For example, using a reporter cell line for screening and functionally validating GLP-1 receptor agonists. Examples of suitable cell lines include the CHO-K1 / GLP1 R / Ga15 reporter cell line (Genscript) which can be used to perform a Calcium flux assay for validation of GLP-1 receptor agonists and the GLP-1 R / CRE Luciferase Reporter HEK293 Cell Line (BPS Bioscience) which can be used to monitor activation of GLP-1 receptor in these cells by measuring luciferase activity.

[0069] Known GLP-1 receptor agonists are reviewed in Lund et al., Eur J Intern Med. (2014) 25(5):407-14, which is hereby incorporated by reference in its entirety. Several known GLP-1 receptor agonists are also listed in Table 1 . These are incretin, incretin-like or incretin-targeting molecules that have clinically demonstrated weight loss abilities. Administration of these molecules is often associated with the undesirable side effect of lean muscle loss. In some embodiments, fusion molecules as described herein comprise a GLP-1 receptor agonist moiety selected from the GLP-1 receptor agonists in Table 1 , fused to a myostatin pathway inhibitor moiety.

[0070] Table 1 - GLP-1 Receptor Agonists

[0071] In some embodiments the GLP-1 receptor agonist moiety is, or comprises, semaglutide (DrugBank Acc. No. DB13928). Semaglutide is a GLP-1 receptor agonist peptide having a Ala8Amino-isobuthyric acid and Lys34Arg modification relative to native GLP-1 and Lys26 is acylated with stearic diacid. Semaglutide has the amino acid sequence: His-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val -Ser-Ser-Tyr-Leu-Glu-Gly-GIn- Ala-Ala-Lys(AEEA-AEEA-y-Glu-Octadecanedioic)-Glu-Phe-lle-Ala-Trp-Leu-Val-Arg-Gly- Arg-Gly (SEQ ID NO: 3). In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 17.

[0072] In some embodiments the GLP-1 receptor agonist moiety is, or comprises, dulaglutide (DrugBank Acc. No. DB09045). Dulaglutide is a GLP-1 receptor agonist peptide having the sequence set out in SEQ ID NO: 4. The first 31 amino acids of this peptide are residues 7-37 of human GLP-1 comprising Ala8Gly, Gly22Glu and Arg36Gly modifications relative to native GLP-1. The next 16 amino acids (GGGGGGGSGGGGSG) are a linker sequence. The remaining 228 amino acids are a synthetic human Fc fragment (immunoglobulin G4). Two identical peptide chains form a dimer, linked by inter-monomer disulphide bonds between Cys55-55 and Cys58-58. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 4.

[0073] In some embodiments the GLP-1 receptor agonist moiety is, or comprises, liraglutide (DrugBank Acc. No. DB06655). Liraglutide is a GLP-1 receptor agonist peptide which has a Lys34Arg modification relative to native GLP-1 and a hexadecanoyl group attached to Lys26 via a glutamic acid spacer. Liraglutide has the amino acid sequence: His-Ala-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-GIn-Ala-Ala- Lys(y-Glu-palmitoyl)-Glu-Phe-lle-Ala-Trp-Leu-Val-Arg-Gly-Arg-Gly (SEQ ID NO: 5). In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 5.

[0074] In some embodiments the GLP-1 receptor agonist moiety is a dual agonist for both GLP-1 and GIP receptors (also called a GLP-1 / GIP receptor co-agonist). In some embodiments the GLP-1 receptor agonist moiety is, or comprises, Tirzepatide (DrugBank Acc. No. DB15171). Tirzepatide is a 39-amino acid peptide which is a dual agonist for both GLP-1 and GIP receptors having the amino acid sequence set out in SEQ ID NO: 6. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 6.

[0075] In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises a-aminoisobutyric acid. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure is a bromoacetyl-GLP-1 analogue peptide (e.g. comprising a Lysine with a bromoacetyl group on its side chain). In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises C-terminal amidation. In some embodiments, the GLP-1 receptor agonist moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 94.

[0076] In some embodiments the GLP-1 receptor agonist moiety is, or comprises, AMG-133 (also known as maridebart cafraglutide). AMG-133 is a GIPR antagonist / GLP-1 receptor agonist bispecific molecule. In some embodiments, the GLP-1 receptor agonist moiety is, or comprises, the GLP-1 moiety of AMG-133 (having the amino acid sequence set out in SEQ ID NO: 7). In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 7. In some embodiments, a fusion molecule according to the present disclosure comprises a GLP-1 receptor agonist and a GIPR antagonist. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 66. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 67. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 66 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 67. In some embodiments the GLP-1 receptor agonist moiety is a dual agonist for both GLP-1 and glucagon receptors (also called a GLP-1 / GCG receptor co-agonist). In some embodiments the GLP-1 receptor agonist moiety is, or comprises, Survodutide (DrugBank Acc. No. DB18989). Survodutide is a 29-amino acid peptide which is a dual agonist for both GLP-1 and glucagon receptors having the amino acid sequence set out in SEQ ID NO: 8. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO:8.

[0077] In some embodiments the GLP-1 receptor agonist moiety is a triple agonist of GLP-1 , GIP, and GCG receptors (also called a GLP-1 / GIP / GCG receptor co-agonist). In some embodiments the GLP-1 receptor agonist moiety is, or comprises, retatrutide (DrugBank Acc. No. DB18993). Retatrutide is a 39-amino acid peptide that is a triple hormone receptor agonist of GLP-1 , GIP, and GCGR receptors. The amino acid sequence of retatrutide is set out in SEQ ID NO: 9. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 9.

[0078] In some embodiments the GLP-1 receptor agonist moiety is, or comprises, albiglutide. Albiglutide is a fusion protein that includes two sequential GLP-1 peptides linked to human albumin. The GLP-1 peptides comprise an Ala8Gly modification relative to native GLP-1. The amino acid sequence of albiglutide is set out in SEQ ID NO: 10. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO:10. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to amino acids 1 to 31 of SEQ ID NO: 10.

[0079] Exenatide (SEQ ID NO: 11) and lixisenatide (SEQ ID NO: 12) are short-acting GLP-1 R agonists which, despite being resistant to degradation by DPP-4 are still subject to renal elimination, which confers a plasma half-life of approximately 2 to 4 h for these agents. In some embodiments, the GLP-1 receptor agonist moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 11 or SEQ ID NO: 12.

[0080] In some embodiments, the GLP-1 receptor agonist moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to an amino acid sequence selected from SEQ ID NOs: 1-12 or 94.

[0081] Other obesity-related peptide moieties

[0082] The obesity-related peptide moiety may be any peptide having an effect on weight loss, e.g. when administered alone or in combination with a GLP-1 receptor agonist. For example, the obesity-related peptide moiety may be a Growth Hormone Releasing Hormone (GHRH) agonist, a GIP receptor agonist or antagonist, a glucagon receptor (GCGR) agonist, an Amylin receptor agonist, or a Peptide YY (PYY) - Y-receptor agonist (e.g. a Y-1 or Y-2 receptor agonist). In some embodiments, a fusion molecule of the present disclosure comprises an obesity-related peptide moiety, wherein the obesity-related peptide moiety is a GHRH or GHRH receptor agonist, a GIP receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a PYY-Y-receptor agonist (e.g. a Y-1 or Y-2 receptor agonist).

[0083] In some embodiments, the obesity-related peptide moiety is a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist.

[0084] In other words, in some embodiments the fusion molecules comprises, or consists of, a Growth Hormone Releasing Hormone (GHRH) agonist fused to a myostatin pathway inhibitor moiety. In some embodiments the fusion molecules comprises, or consists of, a GIP receptor agonist or antagonist fused to a myostatin pathway inhibitor moiety. In some embodiments the fusion molecules comprises, or consists of, a glucagon receptor (GCGR) agonist fused to a myostatin pathway inhibitor moiety. In some embodiments the fusion molecules comprises, or consists of, an Amylin receptor agonist fused to a myostatin pathway inhibitor moiety. In some embodiments the fusion molecules comprises, or consists of, a Peptide YY (PYY) agonist fused to a myostatin pathway inhibitor moiety.

[0085] In some embodiments, a fusion molecule according to the present disclosure comprises, or consist of:

[0086] (i) an obesity-related peptide moiety, wherein the obesity-related peptide moiety is a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist; and

[0087] (ii) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an IgG-type antigen binding molecule.

[0088] GLP-1 is recognized as the core of obesity-related treatment. However, it has been shown that targeting multiple modes-of-action in addition to GLP-1 gives synergistic results in terms of total weight loss. In any of the embodiments described herein, a fusion molecule comprising a GLP-1 receptor agonist moiety may further comprise an obesity-related peptide moiety ( / .e. another obesity-related peptide in addition to a GLP-1 receptor agonist moiety). Accordingly, in some embodiments, a fusion molecule as described herein further comprises a first obesity-related peptide moiety and a second obesity-related peptide moiety (e.g. a first obesity-related peptide moiety, wherein the first obesity-related peptide moiety is a GLP-1 receptor agonist moiety and a second obesity-related peptide moiety). As used herein, the term ‘obesity-related peptide moiety’ is interchangeable with the term ‘further obesity related peptide’. In some embodiments, the obesity-related peptide moiety is, or comprises, a GHRH agonist. As used herein, the term “GHRH agonist” encompasses GHRH receptor agonists. In some embodiments, the GHRH agonist comprises, or consists of, an amino acid sequence according to SEQ ID NO: 13 or SEQ ID NO: 99. In some embodiments, the obesity-related peptide moiety is, or comprises, the GHRH receptor agonist Tesamorelin (SEQ ID NO: 13). In some embodiments, Tesamorelin comprises or consists of an amino acid sequence having an Ala2Gly amino acid substitution relative to SEQ ID NO: 13. Accordingly, in some embodiments the obesity-related peptide moiety comprises, or consists of, an amino acid sequence according to SEQ ID NO: 14. In some embodiments, the Tesamorelin comprises or consists of an amino acid sequence having an Ala2Val amino acid substitution relative to SEQ ID NO: 13. Accordingly, In some embodiments the obesity-related peptide moiety comprises, or consists of, an amino acid sequence according to SEQ ID NO: 15.

[0089] In some embodiments, the obesity-related peptide moiety is, or comprises, a GIP receptor agonist. In some embodiments the GIP receptor agonist comprises, or consists of, an amino acid sequence according to SEQ ID NO: 16. In some embodiments, the GIP receptor agonist comprises, or consists of, an amino acid sequence having an Ala2Gly amino acid substitution relative to SEQ ID NO: 16. Accordingly, in some embodiments the obesity-related peptide moiety comprises or consists of an amino acid sequence according to SEQ ID NO: 17, SEQ ID NO: 96 or SEQ ID NO: 97. In some embodiments, the GIP receptor agonist comprises, or consists of, an amino acid sequence having an Ala2Val amino acid substitution relative to SEQ ID NO: 16. Accordingly, in some embodiments the obesity-related peptide moiety comprises, or consists of, an amino acid sequence according to SEQ ID NO: 18. In some embodiments, the obesity-related peptide moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to any one of SEQ ID NOs: 16, 17, 18, 96 or 97.

[0090] In some embodiments, the obesity-related peptide moiety is, or comprises, a GIP receptor antagonist. In some embodiments the GIP receptor antagonist comprises, or consists of, an amino acid sequence according to SEQ ID NO: 19. In some embodiments, the obesity-related peptide moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 19.

[0091] In some embodiments, the obesity-related peptide moiety is, or comprises, a glucagon (GCG) agonist. In some embodiments the glucagon receptor agonist comprises, or consists of, an amino acid sequence according to SEQ ID NO: 20. In some embodiments the glucagon receptor agonist comprises an Exendin 4 fragment (GCG-EX) to increase solubility. In some embodiments the glucagon receptor agonist comprises, or consists of, an amino acid sequence according to or SEQ ID NO: 98. In some embodiments, the glucagon receptor agonist comprises or consists of an amino acid sequence having a Ser2Gly amino acid substitution relative to SEQ ID NO: 20 or SEQ ID NO: 98. Accordingly, in some embodiments the obesity-related peptide moiety comprises or consists of an amino acid sequence according to SEQ ID NO: 21 . In some embodiments, the glucagon receptor agonist comprises, or consists of, an amino acid sequence having an Ser2Val amino acid substitution relative to SEQ ID NO: 20 or SEQ ID NO: 98. Accordingly, In some embodiments the obesity-related peptide moiety comprises or consists of an amino acid sequence according to SEQ ID NO: 22. In some embodiments, the obesity- related peptide moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 20 or SEQ ID NO: 98.

[0092] In some embodiments, the obesity-related peptide moiety is, or comprises, an amylin receptor agonist. For example, an amylin receptor agonist as described in patent: US 5,739,106 A. In some embodiments the amylin receptor agonist comprises, or consists of, an amino acid sequence according to SEQ ID NO: 23 or SEQ ID NO: 100. In some embodiments, the obesity-related peptide moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 23 or SEQ ID NO: 100.

[0093] In some embodiments, the obesity-related peptide moiety is, or comprises, a PYY agonist. In some embodiments the PYY agonist comprises or consists of an amino acid sequence according to SEQ ID NO: 24. In some embodiments, the obesity-related peptide moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 24.

[0094] In some embodiments, the obesity-related peptide moiety is, or comprises, a PYY Y-2 receptor selective agonist. In some embodiments the PYY Y-2 receptor selective agonist comprises, or consists of, an amino acid sequence according to SEQ ID NO: 25. In some embodiments, the obesity-related peptide moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 25.

[0095] In any of the embodiments described herein, the fusion protein may comprise a peptide moiety that simultaneously targets GLP-1 and any of the components aforementioned hereinabove. For example, a multi (e.g. dual / tri)-agonist comprising a GLP-1 receptor agonist and one or more other obesity-related peptide moieties as described herein.

[0096] In some embodiments, the fusion molecule comprises a peptide comprising, or consisting of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to an amino acid sequence selected from any one of SEQ ID NOs: 13-25.

[0097] In some embodiments, the obesity-related peptide moiety is fused to the N-terminus of the myostatin pathway inhibitor moiety. For example, when the myostatin pathway inhibitor moiety is an antibody (e.g. an IgG-type antibody), the obesity-related peptide moiety is fused to the N-terminus of the heavy chain of the antibody, or the N-terminus of the light chain of the antibody. In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antibody that binds to a myostatin pathway protein, and the obesity-related peptide moiety is fused to a constituent polypeptide of the antibody that binds to a myostatin pathway protein. In some embodiments the myostatin pathway inhibitor moiety is, or comprises, an antibody (e.g. an antibody that binds to a myostatin pathway protein) comprising an antibody heavy chain, wherein the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain. In such embodiments, the obesity-related peptide moiety is fused to the N-terminus of the myostatin pathway inhibitor moiety directly or via any linker as described herein.

[0098] In some embodiments, the obesity-related peptide moiety is fused to the C-terminus of the myostatin pathway inhibitor moiety. For example, when the myostatin pathway inhibitor moiety is an antibody, the obesity-related peptide moiety may be fused to the C-terminus of the light chain of the antibody. In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antibody that binds to a myostatin pathway protein, and the obesity-related peptide moiety is fused to a constituent polypeptide of the antibody that binds to a myostatin pathway protein. In some embodiments the myostatin pathway inhibitor moiety is, or comprises, an antibody (e.g. an antibody that binds to a myostatin pathway protein) comprising an antibody light chain, wherein the obesity-related peptide moiety is fused to the C-terminus of the antibody light chain.

[0099] In some embodiments, the fusion molecule comprises an Fc region and the obesity-related peptide moiety is fused to the Fc region. For example, an obesity-related peptide moiety is fused to the N- terminus of the Fc region. In some embodiments, the Fc fragment comprises or consists of a CH2 and CH3 region, and the obesity-related peptide moiety is fused to the N-terminus of the CH2 region.

[0100] In some embodiments, the fusion molecule comprises, or consists of, a polypeptide complex, comprising:

[0101] (i) a first polypeptide that comprises a GLP-1 receptor agonist moiety fused to an Fc region; and

[0102] (ii) a second polypeptide comprises an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist, fused to an Fc region.

[0103] In such embodiments the GLP-1 receptor agonist moiety and / or the obesity-related peptide moiety may be fused to the CH2 region of the Fc region of the first and second polypeptide.

[0104] Muscle-Preserving Molecules

[0105] Myostatin pathway inhibitors

[0106] Myostatin (also called GDF-8) is a transforming growth factor-p (TGF-p) superfamily member that normally functions to limit skeletal muscle mass. The function of myostatin in muscle is at least partially redundant with that of another TGF-p family member, activin A. The structure and function of myostatin (also known as MSTN and growth differentiation factor 8 (GDF8)) is described e.g. in Knapp et al., Biomolecules (2023) 13(12):1777, Baig et al., Front Physiol. (2022) 13:876078 and Yang et al., Front Endocrinol (Lausanne). (2023) 14:1181913, all of which are hereby incorporated by reference in their entirety.

[0107] Activins are multifunctional proteins belonging to the transforming growth factor-beta (TGF-p) superfamily and are formed by the dimerization of p subunits. The primary isoforms - activin A (pA-pA), activin B (pB- pB), and the more recently-characterized activin E (pE-pE) - play diverse roles in development, tissue homeostasis, metabolism, inflammation, and disease. Activin A and Activin B can also form a heterodimer (pA-pB), known as activin AB. The structure and function of activins is described e.g. in Lodberg, Cytokine Growth Factor Rev. (2021) 60:1-17, Bloise et al., Physiol Rev. (2019) 99(1):739-780, Wang et al., Hepatol Commun. (2022) 6(10):2812-2826, Park et al., Exp Mol Med. (2025) 57(2): 466-477 and Vestal et al., Biochem J. (2024) 481 (7):547-564, all of which are hereby incorporated by reference in their entirety.

[0108] Myostatin, and activins bind transmembrane activin type 2 receptors and activate downstream signaling. There are two activin type 2 receptors; activin receptor type-2A (ActRIIA; also known as ActR2A, ACVR2A, ACVRIIA, Activin 2A receptor) and activin receptor type-2B (ActRIIB; also known as ActR2B, ACVR2B, ACVRIIB, Activin 2B receptor). The structure and function of activin receptors is described e.g. in Lodberg, Cytokine Growth Factor Rev. (2021) 60:1-17, Han. Vitam Horm. (2011) 85:29-38, Walton et al., Mol Cell Endocrinol. (2012) Aug 15;359(1 -2):2-12, all of which are hereby incorporated by reference in their entirety.

[0109] The circulating form of myostatin (‘latent myostatin’) is produced from the inactive precursor of myostatin (‘pro-myostatin’) by furin proteases. Latent myostatin is a latent complex of the myostatin C-terminal dimer noncovalently bound to the myostatin N-terminal propeptide domain, which inhibits the biological activity of the C-terminal domain. Following cleavage of the propeptides, the mature C-terminal myostatin dimer (‘active myostatin’) can bind to ActRIIB.

[0110] ActRIIA / B in turn activate activin receptor-like kinase 4 (ALK4) or ALK5 receptor. Subsequent downstream signalling via SMAD transcription factor complexes results in negative regulation of skeletal muscle growth. Various lines of evidence indicate that inhibition of ActRII or downstream signaling molecules can promote skeletal muscle growth. For example, inhibition of myostatin / activin A signaling using a soluble ActRIIB resulted in increased bone and muscle mass in mice that were sent to the International Space Station (Lee et al. Proc Natl Acad Sci U S A. (2020) 117(38):23942-23951).

[0111] The term ‘myostatin pathway inhibitors’ is used herein to describe inhibitors targeting one or more components of the myostatin / activin A signalling pathway (also known as the activin A / myostatin-Activin 2A / 2B receptor axis). For example, the term ‘myostatin pathway inhibitors’ includes inhibitors of myostatin (which can be inhibitors of pro-myostatin, active myostatin, latent myostatin or combinations thereof e.g. inhibitors of both active and latent myostatin, inhibitors of both pro- and latent myostatin, inhibitors of both active and pro-myostatin, or inhibitors of active, latent and pro-myostatin), inhibitors of Activin A, inhibitors of ActRIIA, inhibitors of ActRIIB, inhibitors of both ActRIIA and ActRIIB, inhibitors of ALK4, or inhibitors of ALK5. In other words, the myostatin pathway inhibitor moiety is, or comprises, an inhibitor of a myostatin pathway protein. In some embodiments the myostatin pathway protein is myostatin, ActRIIA, ActRIIB, ActRIIA and ActRIIB, Activin A, ALK4 or ALK5.

[0112] It will be appreciated that the term ‘moiety’ as used herein is not intended to be limiting. By way of illustration, the essential element of a myostatin pathway inhibitor moiety as described herein is a myostatin pathway inhibitor as described herein.

[0113] In some embodiments, the myostatin pathway inhibitor is, or comprises, an inhibitor of a myostatin, an inhibitor of an activin or an inhibitor of an activin receptor.

[0114] In some embodiments, a myostatin according to the present disclosure is prepromyostatin, promyostatin, latent myostatin or active myostatin. In some embodiments, a myostatin is promyostatin, latent myostatin or active myostatin. In some embodiments, a myostatin is latent myostatin or active myostatin. In some embodiments, a myostatin is active myostatin.

[0115] In some embodiments, an activin according to the present disclosure is selected from: activin A, activin B, activin AB, activin E, activin C, activin AC and activin BC. In some embodiments, an activin according to the present disclosure is selected from: activin A, activin B, activin AB and activin E. In some embodiments, an activin is activin A. In some embodiments, an activin is activin B. In some embodiments, an activin is activin AB. In some embodiments, an activin is activin E. In some embodiments, an activin is activin C. In some embodiments, an activin is activin AC. In some embodiments, an activin is activin BC.

[0116] In some embodiments, an activin receptor according to the present disclosure is selected from: ACVR1C, ACVR2A and ACVR2B. In some embodiments, an activin receptor is selected from: ACVR2A and ACVR2B. In some embodiments, the activin receptor is both ACVR2A and ACVR2B. In some embodiments, an activin receptor is ACVR1C. In some embodiments, an activin receptor is ACVR2A. In some embodiments, an activin receptor is ACVR2B.

[0117] In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an inhibitor of promyostatin, active myostatin, latent myostatin, both active and latent myostatin, Activin A, ActRIIA, ActRIIB, both ActRIIA and ActRIIB, ALK4 or ALK5. For example, in some embodiments the myostatin pathway inhibitor moiety is, or comprises, a peptide or polypeptide inhibitor of pro-myostatin, active myostatin, latent myostatin, both active and latent myostatin, both pro- and latent myostatin, both active and pro-myostatin, or active, latent and pro-myostatin, Activin A, ActRIIA, ActRIIB, both ActRIIA and ActRIIB, ALK4 or ALK5.

[0118] In some embodiments, fusion molecules according to the present disclosure comprise multiple different myostatin pathway inhibitors, e.g. inhibitors against more than one component of the myostatin pathway. For example, an inhibitor of myostatin and an inhibitor of another family member (e.g. activin). It has been suggested that this may help achieve maximum lean mass preservation, for example the combination of trevogrumab and garetosmab is being tested in the clinic (Gonzalez Trotter et al., Diabetes (2024); 73 (Supplement "!): 34-OR). Myostatin inhibitors and clinical trial outcomes are reviewed e.g. in Suh et al., J Bone Metab. (2020) 27(3):151 -165, which is hereby incorporated by reference in its entirety. Suitable myostatin pathway inhibitors can also be readily identified by those skilled in the art. For example, using a reporter cell line for screening and functionally validating myostatin pathway inhibitors. For example, the TGFp / Activin A- Responsive Luciferase Reporter HEK293 Cell Line (BPS Bioscience) is a HEK293 cell line expressing the Firefly luciferase reporter under the control of SMAD-responsive elements (SMAD binding elements, SBE) which can be used to detect inhibition of the myostatin pathway.

[0119] Known muscle-preserving molecules are listed in Table 2. In some embodiments, fusion molecules as described herein comprise an obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety selected from the muscle-preserving molecules listed in Table 2. In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, Apitegromab (DrugBank Acc. No. DB16096), GYM329 (DrugBank Acc. No. DB18590), Taldefgrobep alfa (DrugBank Acc. No. DB16337), KER-065, Trevogrumab (DrugBank Acc. No. DB15159), Garetosmab (DrugBank Acc. No. DB16379), Bimagrumab (DrugBank Acc. No. DB12584), BIO101 , and Tesamorelin (DrugBank Acc. No. DB08869).

[0120] Table 2 - Muscle-preserving molecules

[0121] Antigen Binding Molecules

[0122] In some embodiments, a myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an antigen-binding molecule. For example, the myostatin pathway inhibitor moiety may comprise, or consist of, an antigen-binding molecule which specifically binds myostatin, Activin A, ActRIIA, ActRIIB, ActRIIA and ActRIIB, ALK4 or ALK5. In some embodiments, the myostatin pathway inhibitor moiety is an anti-myostatin antigen-binding molecule.

[0123] An ‘antigen-binding molecule’ refers to a molecule that binds to a given antigen. Antigen-binding molecules include antigen-binding polypeptides and antigen-binding polypeptide complexes such as antibodies ( / .e. immunoglobulins (Igs)) and antigen-binding fragments thereof. In some embodiments, a myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an antigen-binding polypeptide or an antigen-binding polypeptide complex. A ‘polypeptide’ is a polymer chain of two or more peptides. Polypeptides typically have a length greater than about 50 amino acids.

[0124] An antigen-binding molecule may comprise more than one polypeptide which together form an antigenbinding domain. The polypeptides may associate covalently or non-covalently. An antigen-binding molecule may refer to a non-covalent or covalent complex of more than one polypeptide (e.g. 2, 3, 4, 6, or 8 polypeptides), e.g. an IgG-like antigen-binding molecule comprising two heavy chain polypeptides and two light chain polypeptides. In some embodiments, the myostatin pathway inhibitor moiety is an IgG type antigen binding molecule. In some embodiments, the polypeptides form part of a larger polypeptide comprising the polypeptides (e.g. in the case of scFv comprising VH and VL, or in the case of scFab comprising VH-CH1 and VL-CL).

[0125] The term ‘antigen-binding molecules’ as used herein also includes receptors, such as ActRIIA and ActRIIB. For example, an antigen-binding molecule according to the present invention may be a decoy receptor. For example, ACE-031 is a soluble form of activin receptor type IIB (ActRIIB) which promotes muscle growth by binding to myostatin and other negative regulators of muscle mass. In some embodiments, the myostatin pathway inhibitor moiety is a decoy receptor, for example a decoy ActRIIA or ActRIIB receptor.

[0126] In some embodiments, a myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an antibody. As used herein, ‘antibodies’ include monoclonal antibodies, polyclonal antibodies, monospecific and multispecific (e.g., bispecific, trispecific, etc.) antibodies, and antibody-derived target-binding molecules such as scFv, scFab, diabodies, triabodies, scFv-Fc, minibodies, single domain antibodies (e.g. VHH), etc. Antigen-binding fragments of antibodies include e.g. Fv, Fab, F(ab’)2 and F(ab’) fragments. Antigen-binding molecules also include polypeptide aptamers, thioredoxins, monobodies, anticalins, Kunitz domains, avimers, knottins, fynomers, atrimers, DARPins, affibodies, nanobodies ( / .e. a single-domain antibodies (sdAbs)), affilins, armadillo repeat proteins (ArmRPs), OBodies and fibronectins - reviewed e.g. in Reverdatto et al., Curr Top Med Chem. (2015) 15(12):1082-1101 , which is hereby incorporated by reference in its entirety (see also e.g. Boersma et al., J Biol Chem. (2011) 286:41273-85 and Emanuel et al., Mabs (2011) 3:38-48).

[0127] Antibodies generally comprise six complementarity-determining regions CDRs; three in the heavy chain variable (VH) region: HC-CDR1 , HC-CDR2 and HC-CDR3, and three in the light chain variable (VL) region: LC-CDR1 , LC-CDR2, and LC-CDR3. The six CDRs together define the paratope of the antibody, which is the part of the antibody that binds to the target antigen. The VH region and VL region comprise framework regions (FRs) either side of each CDR, which provide a scaffold for the CDRs. From N-terminus to C-terminus, VH regions comprise the following structure: N term-[HC-FR1]-[HC-CDR1]-[HC-FR2]-[HC-CDR2]-[HC-FR3]-[HC-CDR3]-[HC-FR4]-C term; and VL regions comprise the following structure: N term-[LC-FR1]-[LC-CDR1]-[LC-FR2]-[LC-CDR2]-[LC-FR3]- [LC-CDR3]-[LC-FR4]-C term.

[0128] There are several different conventions for defining antibody CDRs and FRs, such as those described in Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD (1991), Chothia et a!., J. Mol. Biol. 196:901-917 (1987), and VBASE2, as described in Retter et al., Nucl. Acids Res. (2005) 33 (suppl 1): D671-D674. The CDRs and FRs of the VH regions and VL regions of the antibody clones described herein were defined according to the international IMGT (ImMunoGeneTics) information system (LeFranc et al., Nucleic Acids Res. (2015) 43 (Database issue):D413-22), which uses the IMGT V-DOMAIN numbering rules as described in Lefranc et al., Dev. Comp. Immunol. (2003) 27:55-77. In preferred embodiments, the CDRs and FRs of antigenbinding molecules referred to herein are defined according to the IMGT information system.

[0129] In some embodiments, the myostatin pathway inhibitor moiety comprises the CDRs, FRs and / or the VH and / or VL regions of an antibody. It will be appreciated that in such embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antibody, and the obesity-related peptide moiety is fused to a constituent polypeptide of the antibody. An antigen-binding molecule may comprise an antibody heavy chain. An “antibody heavy chain” is a polypeptide comprising from N- to C-terminus: a VH followed by a heavy chain constant region comprising three constant regions (CH1 , CH2, and CH3). Accordingly, in some embodiments is a fusion molecule comprising an obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain. An antigen-binding molecule may comprise an antibody light chain. An “antibody light chain” is a polypeptide comprising from N- to C-terminus: a VL followed by a CL. Accordingly, in some embodiments is a fusion molecule comprising an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody light chain. In some embodiments is a fusion molecule comprising an obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain and an antibody light chain.

[0130] In some embodiments, an antigen-binding molecule comprises an antibody heavy chain variable region (VH) and an antibody light chain variable region (VL) of an antibody capable of specific binding to a given target molecule. An antigen-binding molecule formed by the VH and VL of a given antibody may also be described as the Fv region of the given antibody.

[0131] Antigen-binding molecules according to the present disclosure may be derived from antibodies. Antibody- derived antigen-binding molecules may comprise, or consist of, the antigen-binding region of an antibody (e.g. an antigen-binding fragment of an antibody). In some embodiments, an antigen-binding molecule may be or may comprise the Fv (e.g. provided as an scFv) or the Fab region of an antibody that binds to a given target, or the whole antibody.

[0132] An antigen-binding molecule may comprise more than one peptide / polypeptide which together form an antigen-binding domain. The peptides / polypeptides may associate to form the antigen-binding domain by protein: protein interaction. By way of example, antigen-binding molecules of the present disclosure may comprise an antigen-binding domain formed by association between: (i) a polypeptide comprising a VH region; and (ii) a polypeptide comprising a VL region. Accordingly, in some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, a polypeptide complex formed by protein: protein interaction between constituent peptides / polypeptides of the antigen-binding molecule.

[0133] In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, a polypeptide complex formed by association between: (i) a polypeptide comprising a GLP-1 receptor agonist and a VH region; and (ii) a polypeptide comprising a VL region. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, a polypeptide complex formed by association between: (i) a polypeptide comprising a VH region, and (ii) a polypeptide comprising a GLP-1 receptor agonist and a VL region.

[0134] Immunoglobulins and their structures are described e.g. in Schroeder and Cavacini J Allergy Clin Immunol. (2010) 125(202): S41-S52, which is hereby incorporated by reference in its entirety. Immunoglobulins of type G ( / .e. IgG) are -150 kDa glycoproteins comprising two heavy chains and two light chains. From N- to C-terminus, the heavy chains comprise a VH followed by a heavy chain constant region comprising three constant regions (CH1 , CH2, and CH3), with a hinge region provided between the CH1 and CH2 regions. IgG light chains comprise a VL followed by a CL. Depending on the heavy chain, immunoglobulins may be classed as IgG (e.g. lgG1 , lgG2, lgG3, lgG4), IgA (e.g. lgA1 , lgA2), IgD, IgE, or IgM. The light chain may be kappa (K) or lambda (A).

[0135] Herein, a ‘CH1 region’ refers to an amino acid sequence corresponding to the CH1 region of an immunoglobulin (Ig), which is the region formed by positions 118 to 215 of the immunoglobulin constant region, according to the EU numbering system (described in Edelman etal., Proc Natl Acad Sci USA (1969) 63(1): 78-85). A ‘hinge region’ refers to an amino acid sequence corresponding to the hinge region of an Ig, which is the region formed by positions 216 to 230 of the immunoglobulin constant region, according to the EU numbering system. A ‘CH2 region’ refers to an amino acid sequence corresponding to the CH2 region of an immunoglobulin (Ig). The CH2 region is the region of an Ig formed by positions 231 to 340 of the immunoglobulin constant region, according to the EU numbering system described in Edelman et al., Proc Natl Acad Sci USA (1969) 63(1):78-85. A ‘CH3 region’ refers to an amino acid sequence corresponding to the CH3 region of an immunoglobulin (Ig). The CH3 region is the region of an Ig formed by positions 341 to 447 of the immunoglobulin constant region, according to the EU numbering system described in Edelman et al., Proc Natl Acad Sci USA (1969) 63(1):78-85. A ‘CH2-CH3 region’ refers to an amino acid sequence corresponding to the CH2 and CH3 regions of an immunoglobulin (Ig). The CH2-CH3 region is the region of an Ig formed by positions 231 to 447 of the immunoglobulin constant region, according to the EU numbering system described in Edelman et al., Proc Natl Acad Sci USA (1969) 63(1):78-85.

[0136] In some embodiments, an antigen-binding molecule according to the present disclosure comprises a CH1 region, a hinge region, a CH2 region and / or a CH3 region. In some embodiments, an antigen-binding molecule comprises one or more polypeptides comprising a CH2-CH3 region. In some embodiments, an antigen-binding molecule comprises one or more polypeptides comprising a CH1-hinge-CH2-CH3 region.

[0137] In some embodiments, an antigen-binding molecule according to the present disclosure comprises an Fc region. As used herein, an ‘Fc region’ refers to a polypeptide complex formed by interaction between two polypeptides, each polypeptide comprising the CH2-CH3 region of an immunoglobulin (Ig) heavy chain constant sequence.

[0138] In some embodiments, a CH2 region, CH3 region and / or a CH2-CH3 region according to the present disclosure corresponds to the CH2 region / CH3 region / CH2-CH3 region of an IgG (e.g. IgG 1 , lgG2, lgG3, lgG4), IgA (e.g. lgA1 , lgA2), IgD, IgE or IgM.

[0139] Antibodies that bind to myostatins are known in the art, and include stamulumab, domagrozumab, REGN1033, GYM329, trevogrumab, apitegromab and anti-myostatin antibody clone APE2480 LYC1 E4 lgG4P. Stamulumab (also known as MYO-029; DrugBank Accession No. DB05915; UNII: V43X8G4797) is a human monoclonal anti-myostatin antibody, which inhibits myostatin activity, and is being developed to treat muscle-wasting diseases including muscular dystrophy and age-related sarcopenia. The amino acid sequences of the heavy chain and light chain polypeptides of stamulumab are available at UNII: V43X8G4797. Domagrozumab (DrugBank Accession No. DB15083; UNII: 516MD5WQ24) is a humanized monoclonal antibody that specifically inhibits myostatin. The amino acid sequences of the heavy and chain light chain polypeptides of domagrozumab are available at UNII: 516MD5WQ24. REGN1033 (also known as SAR391786) is a fully human monoclonal antibody that blocks myostatin activity, and is described e.g. in Latres et al., Skelet Muscle. (2015) 5:34, which is hereby incorporated by reference in its entirety. GYM329 (DrugBank Accession No. DB18590) is a humanized monoclonal lgG1 antibody that binds to human latent myostatin in a pH-dependent manner, and is described e.g. in Muramatsu et al., Sci Rep. (2021) 11 :2160, which is hereby incorporated by reference in its entirety. Trevogrumab (DrugBank Accession No. DB15159; UNII: 87T4327873) is a human monoclonal anti- myostatin antibody being developed for the treatment of muscle atrophy. The amino acid sequences of the heavy chain and light chain polypeptides of trevogrumab are available at UNII: 87T4327873.

[0140] Apitegromab (DrugBank Accession No. DB16096; UNII: UZ54216N0Y) is a human monoclonal antibody that binds to and inhibits promyostatin. The amino acid sequences of the heavy and chain light chain polypeptides of apitegromab are available at UNII: UZ54216N0Y. Anti-myostatin antibody clone APE2480 LYC1 E4 lgG4P is a human monoclonal antibody that binds to and inhibits myostatin. The amino acid sequences of the heavy chain and light chain polypeptides of anti-myostatin antibody clone APE2480 LYC1 E4 lgG4P are set out in the PCT publication WO 2014 / 172448 A2. Landogrozumab (also known as LY2495655; DrugBank Accession No. DB11862; UNII: V43X8G4797) is a human monoclonal anti- myostatin antibody, which inhibits myostatin activity, and is being developed to treat muscle-wasting diseases including cancer cachexia.

[0141] Antibodies that bind to activins are known in the art. Anti-activin A antibodies include garetosmab (DrugBank Accession No. DB16379; UNII: KR9ZSKO5QE), which is a human monoclonal antibody that binds to and neutralises activin A. The amino acid sequences of the heavy and chain light chain polypeptides of garetosmab are available at UNII: KR9ZSKO5QE. Anti-activin A antibodies are also disclosed in WO 2008 / 031061 A2 and WO 2015 / 017576 A1 , which are hereby incorporated by reference in their entirety. Anti-activin A antibodies include A1-A14 (A1) disclosed in US 8309082 B2. The heavy and light chain sequences of A1 are set out in SEQ ID NO: 97 and 78, respectively. Anti-activin B antibodies include MAB659 (Clone 146807) from R&D Systems. Anti-activin E antibodies include IBIO- 600 (IBio, Inc.).

[0142] Antibodies that bind to activin receptors are known in the art. Anti-activin receptor type II (ActRII) antibodies include bimagrumab (DrugBank Accession No. DB12584; UNII: N15SW1 DIV8), and LAE-123 (Laekna Therapeutics(Shanghai) Co., Ltd.) which are a human monoclonal antibodies that target ACVR2A and ACVR2B simultaneously. The amino acid sequences of the heavy chain and light chain polypeptides of bimagrumab are available at UNII: N15SW1 DIV8. Anti-ACVR2A antibodies include Human Activin RIIA Antibody from R&D Systems (Catalog # AF340) and LAE-102, Human Activin RIIA Antibody from Laekna Therapeutics(Shanghai) Co., Ltd. Anti-ACVR2B antibodies are also disclosed in WO 2014 / 172448 A2, which is hereby incorporated by reference in its entirety. Anti-ACVR2B antibodies include ANB-012 (AnaptysBio), which refers to clone APE2990-4357 / 4361 described in WO 2014 / 172448 A2. Anti-ACVR2B antibodies are also disclosed in WO 2013 / 063536 A1 , which is hereby incorporated by reference in its entirety.

[0143] The skilled person is readily able to produce / obtain further antibodies that bind to a given target antigen (e.g. myostatins, activins, activin receptors), in view of techniques that are well-known in the art. For example, Park and Smolen, Advances in Protein Chemistry (2001) 56: 369-421 describes approaches to the production of monoclonal antibodies suitable for use in humans, including raising xenogeneic antibodies by immunisation of non-human animals and their subsequent chimerisation and / or humanisation, identification by human antibody gene-phage display, and production of antibodies in transgenic mice harbouring human antibody genes.

[0144] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule selected from bimagrumab, landogrozumab, ANB-012, apitegromab, GYM329, trevogrumab or garetosmab.

[0145] In some embodiments the myostatin pathway inhibitor moiety is bimagrumab. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 52. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 53. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 52, and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 53.

[0146] In some embodiments the myostatin pathway inhibitor moiety is apitegromab. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 54. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 55. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 54, and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 55.

[0147] In some embodiments the myostatin pathway inhibitor moiety is trevogrumab. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 56. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 57. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 56, and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 57.

[0148] In some embodiments the myostatin pathway inhibitor moiety is garetosmab. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 58. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 59. In some embodiments, the myostatin pathway inhibitor moiety according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 58, and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 59.

[0149] Muscle-preserving moieties

[0150] In some embodiments, the fusion molecules of the present disclosure further comprise a musclepreserving moiety. As used herein, the term “muscle-preserving moiety” encompasses moieties which stimulate muscle growth. As used herein, the term ‘muscle-preserving moiety’ is interchangeable with the term ‘further muscle-preserving molecule’. In some embodiments, a muscle-preserving moiety according to the present disclosure is a myostatin pathway inhibitor. In other words, in some embodiments, the fusion molecules of the present disclosure comprise more than one myostatin pathway inhibitor. In some embodiments, the muscle-preserving moiety is non-identical to the myostatin pathway inhibitor moiety.

[0151] In some embodiments, a muscle-preserving moiety according to the present disclosure comprises, or consists of, an antigen-binding molecule. For example, fusion molecules of the present disclosure may comprise more than one antibody or antibody-derived target-binding molecule {e.g. scFv, scFab, diabodies, triabodies, scFv-Fc, minibodies or single domain antibodies e.g. VHH, also called nanobodies)). In some embodiments, a muscle-preserving moiety according to the present disclosure is a scFv or a nanobody. In some embodiments, a muscle-preserving moiety according to the present disclosure is a scFv or a nanobody that binds a myostatin pathway protein. In some embodiments, the muscle-preserving moiety is a scFv or a nanobody which binds myostatin, activin A, ActRIIA, ActRIIB, ActRIIA and ActRIIB, ALK4 or ALK5. In some embodiments, the muscle-preserving moiety is a scFv or a nanobody which binds Activin A.

[0152] In some embodiments, a fusion molecule of the present disclosure comprises an antibody and an antibody-derived target-binding molecule {e.g. a myostatin pathway inhibitor antibody and a musclepreserving moiety comprising or consisting of an antibody-derived target-binding molecule).

[0153] In some embodiments, a fusion molecule of the present disclosure comprises an antibody and an scFv {e.g. a myostatin pathway inhibitor antibody and a muscle-preserving moiety comprising or consisting of an scFv). In some embodiments, a fusion molecule of the present disclosure comprises an antibody and a nanobody {e.g. a myostatin pathway inhibitor antibody and a muscle-preserving moiety comprising or consisting of a nanobody). In some embodiments, a fusion molecule of the present disclosure comprises an anti-myostatin antibody and an anti-activin A, anti-ACVR2B or anti-ACVR2A scFv or nanobody. In some embodiments, a fusion molecule of the present disclosure comprises an anti-activin A antibody and an anti-ACVR2B or anti-ACVR2A scFv or nanobody.

[0154] In some embodiments, the muscle-preserving moiety comprises, or consists of, a bimagrumab scFv, a garestomab scFv, a trevogrumab scFv or an apitegromab scFv. In some embodiments, a fusion molecule of the present disclosure comprises (i) an antibody and (ii) an scFv selected from a bimagrumab scFv, a garestomab scFv, a trevogrumab scFv or an apitegromab scFv.

[0155] In some embodiments the muscle-preserving moiety is, or comprises, a bimagrumab scFv. In some embodiments, the muscle-preserving moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 48.

[0156] In some embodiments the muscle-preserving moiety is, or comprises, a garestomab scFv. In some embodiments, the muscle-preserving moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 49.

[0157] In some embodiments the muscle-preserving moiety is, or comprises, a trevogrumab scFv. In some embodiments, the muscle-preserving moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 50.

[0158] In some embodiments the muscle-preserving moiety is, or comprises, an apitegromab scFv. In some embodiments, the muscle-preserving moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 51.

[0159] In some embodiments, a fusion molecule of the present disclosure comprises an antibody and a VHH (e.g. a myostatin pathway inhibitor antibody, and a muscle-preserving moiety which is a myostatin pathway inhibitor comprising or consisting of a VHH).

[0160] In some embodiments, the muscle-preserving moiety is fused to the C-terminus of the myostatin pathway inhibitor moiety. In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, an antibody that binds to a myostatin pathway protein, wherein the muscle-preserving moiety is fused to the C-terminus of a constituent polypeptide of the antibody that binds to a myostatin pathway protein. For example, in some embodiments, the myostatin pathway inhibitor moiety is an antibody e.g. an IgG-type antibody), and the muscle-preserving moiety is connected to the C-terminus of the heavy chain of the antibody (e.g. the C-terminus of the CH3 region). The muscle-preserving moiety may be fused to the C- terminus of the myostatin pathway inhibitor moiety directly or via any linker as described herein. In other words, the myostatin pathway inhibitor moiety is an antibody comprising an antibody heavy chain and an antibody light chain, and the fusion molecule is a polypeptide complex comprising:

[0161] (i) a first polypeptide comprising, or consisting of, an antibody heavy chain and a muscle-preserving moiety, wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain, and

[0162] (ii) a second polypeptide comprising, or consisting of, the antibody light chain.

[0163] In other words, in some embodiments the first polypeptide comprises from N- to C-terminus a VH, CH1 region, CH2 region, CH3 region and a muscle-preserving moiety (e.g. a scFv).

[0164] In some embodiments, the fusion molecule is a polypeptide complex comprising:

[0165] (i) a first polypeptide, comprising: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and a muscle-preserving moiety, wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain, and

[0166] (ii) a second polypeptide, comprising the antibody light chain of the antibody that binds to a myostatin pathway protein.

[0167] In some embodiments, a fusion molecule of the present disclosure comprises an antibody and an antibody-derived target-binding molecule (e.g. wherein the myostatin pathway inhibitor moiety is, or comprises, an antibody, and the fusion molecule further comprises a muscle-preserving moiety comprising, or consisting of, an antibody-derived target-binding molecule), wherein the antibody-derived target-binding molecule is connected to the C-terminus of the heavy chain of the antibody. In some embodiments, a fusion molecule of the present disclosure comprises an antibody and an scFv (e.g. a myostatin pathway inhibitor moiety antibody and a muscle-preserving moiety comprising, or consisting of, an scFv), wherein the scFv is connected to the C-terminus of the heavy chain of the antibody. In some embodiments, a fusion molecule of the present disclosure comprises an antibody and a VHH (e.g. a myostatin pathway inhibitor moiety antibody and a muscle-preserving moiety comprising, or consisting of, a VHH), wherein the VHH is connected to the C-terminus of the heavy chain of the antibody.

[0168] In some embodiments, the muscle-preserving moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to any one of SEQ ID NOs: 48-51 fused to the C-terminus of the myostatin pathway inhibitor moiety.

[0169] In some embodiments, the fusion molecule comprises an antibody comprising a heavy chain, and a muscle-preserving moiety is fused to the antibody heavy chain. For example, a muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain.

[0170] In some embodiments, the fusion molecule comprises an Fc region and a muscle-preserving moiety is fused to the Fc region. For example, a muscle-preserving moiety is fused to the C-terminus of the Fc region. Half-life promoting components

[0171] Fusion molecules of the present disclosure may comprise a half-life promoting component. One approach to half-life extension is fusion of a peptide to an Fc-fragment. For instance, Dulaglutide comprises a GLP- 1 receptor agonist peptide fused to an Fc-fragment (hlgG4) and has a half-life to around 5-8 days. This is significantly higher than native GLP-1 which is rapidly degraded in vivo by DPP-4. Therefore, fusion to an Fc fragment is a strategy for increasing the biological potency of the GLP-1 moiety.

[0172] In some embodiments, the fusion molecules of the present disclosure comprise an Fc region. As used herein, an ‘Fc region’ refers to a polypeptide complex formed by interaction between two polypeptides, each polypeptide comprising the CH2-CH3 region of an immunoglobulin (Ig) heavy chain constant sequence.

[0173] Fc Modifications

[0174] In some embodiments - particularly embodiments in which the fusion molecule is a multi-agonist - the fusion molecule comprises an Fc region comprising modification in one or more of the CH2 and CH3 regions promoting association of the Fc region. Recombinant co-expression of constituent polypeptides of an antigen-binding molecule and subsequent association leads to several possible combinations. To improve the yield of the desired combinations of polypeptides in antigen-binding molecules in recombinant production, it is advantageous to introduce in the Fc regions modification(s) promoting association of the desired combination of heavy chain polypeptides. Modifications may promote e.g. hydrophobic and / or electrostatic interaction between CH2 and / or CH3 regions of different polypeptide chains. Suitable modifications are described e.g. in Ha et al., Front Immnol. (2016) 7:394, which is hereby incorporated by reference in its entirety.

[0175] In some embodiments, the antigen-binding molecule of the present disclosure comprises an Fc region comprising paired substitutions in the CH3 regions of the Fc region according to one of the following formats, as shown in Table 1 of Ha et al., Front. Immnol (2016) 7:394: KiH, KiHs-s, HA-TF, ZW1 , 7.8.60, DD-KK, EW-RVT, EW-RVTS-S, SEED or A107.

[0176] In some embodiments, the fusion molecule of the present disclosure is provided with an Fc region comprising the ‘knob-into-hole’ or ‘KiH’ modification, e.g. as described e.g. in US 7,695,936 and Carter, J Immunol Meth. (2001) 248:7-15. In such embodiments, one of the CH3 regions of the Fc region comprises a ‘knob’ modification, and the other CH3 region comprises a ‘hole’ modification. The ‘knob’ and ‘hole’ modifications are positioned within the respective CH3 regions so that the ‘knob’ can be positioned in the ‘hole’ in order to promote heterodimerisation (and inhibit homodimerisation) of the polypeptides and / or stabilise heterodimers. Knobs are constructed by substituting amino acids having small chains with those having larger side chains (e.g. tyrosine or tryptophan). Holes are created by substituting amino acids having large side chains with those having smaller side chains (e.g. alanine or threonine).

[0177] In some embodiments, one of the CH3 regions of an Fc region of the present disclosure comprises the substitution T366W (numbering of positions / substitutions in the Fc, CH2 and CH3 regions herein is according to the EU numbering system as described in Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD, 1991), and the other CH3 region of the Fc region comprises the substitution Y407V. In some embodiments, one of the CH3 regions of the Fc region comprises the substitution T366W, and the other CH3 region comprises the substitutions T366S and L368A. In some embodiments, one of the CH3 regions of the Fc region comprises the substitution T366W, and the other CH3 region comprises the substitutions Y407V, T366S and L368A.

[0178] In some embodiments, one of the CH3 regions of an Fc region according to the present disclosure comprises the substitution S354C, and the other CH3 region comprises the substitution Y349C. Introduction of these cysteine residues results in formation of a disulphide bridge between the two CH3 regions of the Fc region, further stabilising the heterodimer (Carter (2001), J Immunol Methods 248, 7- 15). In some embodiments, an Fc region according to the present disclosure comprises the ‘KiHs-s’ modification. In some embodiments, one of the CH3 regions of the Fc region comprises the substitutions S354C and T366W (‘knob’ Fc), and the other CH3 region comprises the substitutions Y349C, Y407V, T366S and L368A (‘hole’ Fc).

[0179] In some embodiments, an Fc region according to the present disclosure comprises the ‘DD-KK’ modification as described e.g. in US 8592562 B2. In some embodiments, one of the CH3 regions comprises the substitutions K392D and K409D, and the other CH3 region of the Fc region comprises the substitutions E356K and D399K. The modifications promote electrostatic interaction between the CH3 regions.

[0180] In some embodiments, an Fc region according to the present disclosure comprises modification as described in Labrijn et al., Proc Natl Acad Sci U S A. (2013) 110(13):5145-50, referred to as ‘Duobody’ format. In some embodiments, one of the CH3 regions comprises the substitution K409R, and the other CH3 region of the Fc region comprises the substitution F405L.

[0181] In some embodiments, an Fc region according to the present disclosure comprises the ‘EEE-RRR’ modification as described in Strop et al., J Mol Biol. (2012) 420(3):204-19. In some embodiments, one of the CH3 regions comprises the substitutions D221 E, P228E and L368E, and the other CH3 region of the Fc region comprises the substitutions D221 R, P228R and K409R.

[0182] In some embodiments, an Fc region according to the present disclosure comprises the ‘EW-RVT’ modification described in Choi etal., Mol Cancer Ther (2013) 12(12):2748-59. In some embodiments, one of the CH3 regions comprises the substitutions K360E and K409W, and the other CH3 region of the Fc region comprises the substitutions Q347R, D399V and F405T.

[0183] In some embodiments, an Fc region according to the present disclosure comprises the ‘SEED’ modification as described in Davis et al., Protein Eng Des Sei (2010) 23(4):195-202, in which p-strand segments of human lgG1 CH3 and IgA CH3 are exchanged. In some embodiments, one of the CH3 regions of an Fc region according to the present disclosure comprises the substitutions S364H and F405A, and the other CH3 region comprises the substitutions Y349T and T394F (see e.g. Moore et al., MAbs (2011) 3(6):546-57).

[0184] In some embodiments, one of the CH3 regions of an Fc region according to the present disclosure comprises the substitutions T350V, L351Y, F405A and Y407V, and the other CH3 region comprises the substitutions T350V, T366L, K392L and T394W (see e.g. Von Kreudenstein et al., MAbs (2013) 5(5):646- 54).

[0185] In some embodiments, one of the CH3 regions of an Fc region according to the present disclosure comprises the substitutions K360D, D399M and Y407A, and the other CH3 region comprises the substitutions E345R, Q347R, T366V and K409V (see e.g. Leaver-Fay et al., Structure (2016) 24(4):641- 51).

[0186] In some embodiments, one of the CH3 regions of an Fc region according to the present disclosure comprises the substitutions K370E and K409W, and the other CH3 region comprises the substitutions E357N, D399V and F405T (see e.g. Choi et al., PLoS One (2015) 10(12):e0145349).

[0187] In some embodiments, a myostatin pathway inhibitor moiety of the present disclosure comprises an Fc region. For example, in some embodiments, a fusion molecule of the present disclosure comprises a myostatin pathway inhibitor moiety, wherein said myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an Fc region. In some embodiments, said Fc region comprises a ‘knob-into-hole’ modification.

[0188] In some embodiments, the fusion molecule is a polypeptide complex comprising or consisting of an obesity-related peptide moiety, a myostatin pathway inhibitor moiety and an Fc-fragment. In some embodiments, said Fc region comprises a ‘knob-into-hole’ modification.

[0189] In some embodiments, the fusion molecule is a multi-agonist polypeptide complex comprising or consisting of a GLP-1 receptor agonist moiety, an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist, a myostatin pathway inhibitor moiety and an Fc-fragment. In some embodiments, said Fc region comprises a ‘knob-into-hole’ modification.

[0190] The amino acid sequence of an Fc region comprising a knob mutation is set out in SEQ ID NO: 46. The amino acid sequence of an Fc region comprising a hole mutation is set out in SEQ ID NO: 47. In some embodiments, the fusion molecules of the present disclosure comprises an Fc region comprising, or consisting of, a polypeptide having an amino acid sequence according to SEQ ID NO: 46 and / or SEQ ID NO: 47. In some embodiments, a fusion molecule of the present disclosure comprises an Fc-region having an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 46.

[0191] In some embodiments, a fusion molecule of the present disclosure comprises an Fc-region having an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 47.

[0192] In some embodiments, a fusion molecule of the present disclosure comprises (i) an Fc-region having an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 46; and (ii) an Fc-region having an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 47.

[0193] In some embodiments, the fusion molecule is a multi-agonist polypeptide complex comprising:

[0194] (i) a first polypeptide comprising, or consisting of, a GLP-1 receptor agonist moiety and a first Fc- fragment; and

[0195] (ii) a second polypeptide comprising, or consisting of, an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist and a second Fc-fragment.

[0196] In some embodiments, said first and second Fc-fragments comprise, or consist of the amino acid sequences according to SEQ ID NO: 46 and SEQ ID NO: 47.

[0197] Design of Fusion Molecules

[0198] In some embodiments, fusion molecules as described herein comprise a GLP-1 receptor agonist moiety selected from the GLP-1 receptor agonists in Table 1 , fused to a myostatin pathway inhibitor moiety selected from the molecules listed in Table 2.

[0199] Fusion molecules as described herein may comprise a GLP-1 receptor agonist moiety and myostatin pathway inhibitor moiety combination which has indicated weight loss without muscle atrophy in a clinical trial. In some embodiments, fusion molecules as described herein comprise a GLP-1 receptor agonist moiety and myostatin pathway inhibitor moiety combination set out in Table 3.

[0200] Table 3: Ongoing Clinical Studies Testing Table 1 x Table 2 Combinations

[0201] Connecting

[0202] As used herein, ‘fused’ encompasses moieties / molecules which are directly connected or are connected via a linker. Accordingly, the obesity-related peptide moiety may be directly connected to the myostatin pathway inhibitor or may be connected via a linker.

[0203] Direct

[0204] In some embodiments, the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is directly connected to the myostatin pathway inhibitor moiety. Accordingly, disclosed herein are fusion molecules comprising a obesity-related peptide moiety directly connected to a myostatin pathway inhibitor moiety.

[0205] ‘Directly connected’ (which may be used interchangeably with ‘directly fused’) as used herein means that the amino acids encoding the individual components (i.e. the obesity-related peptide moiety and myostatin pathway inhibitor moiety) are adjacent to each other. Accordingly, in some embodiments, a polynucleotide as described herein comprises an amino acid encoding the obesity-related peptide moiety adjacent to an amino acid encoding the myostatin pathway inhibitor moiety. In such embodiments, a fusion molecule comprising an obesity-related peptide moiety, fused to a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is a peptide or polypeptide, has a peptide bond between the last amino acid of the obesity-related peptide moiety and the first amino acid of the myostatin pathway inhibitor moiety. In other words, a single polypeptide with two domains is created, i.e. a polypeptide having a obesity-related peptide moiety domain and a myostatin pathway inhibitor moiety domain.

[0206] The terms ‘first’ and ‘last’ amino acids as used herein depends on the orientation of the obesity-related peptide moiety and the myostatin pathway inhibitor peptide or polypeptide. It will be appreciated that when the C-terminus of the obesity-related peptide moiety is directly connected to the N-terminus of the myostatin pathway inhibitor peptide or polypeptide, a fusion molecule comprising a obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety has a peptide bond between the last (i.e. C- terminal) amino acid of the obesity-related peptide moiety and the first (i.e. N-terminal) amino acid of the myostatin pathway inhibitor moiety.

[0207] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule, and the obesity-related peptide moiety (e.g. a GLP-1 receptor agonist peptide or polypeptide) is directly connected to the antigen-binding molecule.

[0208] In some embodiments, the antigen-binding molecule is a single polypeptide (e.g. a scFv) and the obesity- related peptide moiety is directly connected to the antigen-binding polypeptide. In such cases, the fusion molecule can form a single polypeptide comprising the obesity-related peptide moiety domain and the myostatin pathway inhibition domain which is an antigen-binding polypeptide. In some embodiments, the antigen-binding molecule is an antigen-binding polypeptide complex and the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is directly connected to a constituent polypeptide of the antigen-binding polypeptide complex. For example, the antigen-binding polypeptide complex may be an IgG type molecule. In such embodiments, the usual arrangement of disulfide bonds is preserved between the heavy and light chains of the molecule. In such embodiments, the obesity-related peptide moiety may be directly connected to (i) a polypeptide comprising a VH region, or (ii) a polypeptide comprising a VL region. For example, the obesity-related peptide moiety may be directly connected to: (i) a polypeptide comprising a VH region, CH1 region, CH2 region and CH3 region, or (ii) a polypeptide comprising a VL region, CH1 region, CH2 region and CH3 region.

[0209] Via linkers

[0210] The fusion molecules of the present disclosure may comprise one or more linker sequences between sequences of amino acids. For example, the obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety) may be connected to the myostatin pathway inhibitor moiety via a linker. Accordingly, disclosed herein are fusion molecules comprising an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety) connected to a myostatin pathway inhibitor moiety via a linker. In some embodiments, an obesity-related peptide moiety and a myostatin pathway inhibitor moiety peptide or polypeptide are connected via a linker. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule and the obesity-related peptide moiety and the myostatin pathway inhibitor moiety antigen-binding molecule are connected via a linker.

[0211] The term “linker” as used herein refers to a component linking the obesity-related peptide moiety and the myostatin pathway inhibitor moiety. That is, the linker according to the present invention refers to the component of the fusion molecule of the present invention that connects the obesity-related peptide moiety and the and the myostatin pathway inhibitor moiety. Linker sequences are known to the skilled person, and are described, for example in Chen et al., Adv Drug Deliv Rev (2013) 65(10): 1357-1369, which is hereby incorporated by reference in its entirety.

[0212] In some embodiments, the linker sequence has a length of 1-2, 1-3, 1-4, 1-5, 1-10, 1-15, 1-20, 1-25, or 1- 30 amino acids. In some embodiments, the linker is a polypeptide linker having a length of 1-2, 1-3, 1-4, 1-5, 1-10, 1-15, 1-20, 1-25, or 1-30 amino acids. In some embodiments, the linker comprises or consists of an amino acid sequence according to any of SEQ ID NOs: 26-45.

[0213] A linker moiety according to the present disclosure may be a cleavable linker moiety or a non-cleavable moiety.

[0214] In some embodiments, a linker moiety according to the present disclosure is a cleavable linker moiety. Cleavable linkers include chemical cleavage linkers (e.g. acid-cleavable linkers, GSH-cleavable linkers, Fe(ll)-cleavable linkers) and enzyme cleavage linkers (e.g. thrombin-cleavable linkers, furin-cleavable linkers, cathepsin-cleavable linkers, glycosidase-cleavable linkers, phosphatase-cleavable linkers, sulfatase-cleavable linkers). In some embodiments, the cleavable linker comprises or consists of an amino acid sequence according to SEQ ID NO: 74.

[0215] In some embodiments, a linker moiety according to the present disclosure is a protease-cleavable linker. In some embodiments, a protease-cleavable linker moiety according to the present disclosure is a furin- cleavable linker. Furin-cleavable linkers can utilize the protease furin in serum to gradually cut and release the GLP-1 receptor agonist from the myostatin pathway inhibitor and therefore preserve the functionality of the myostatin pathway inhibitor after the cleavage occurs. In some embodiments, the furin- cleavable linker comprises or consists of a SPRVRRSV (SEQ ID NO: 26), SPRRARSV (SEQ ID NO: 27), SPRAARSV (SEQ ID NO: 28), SPRSVRSV (SEQ ID NO: 29), or SPRSRRDF (SEQ ID NO: 30) amino acid sequence.

[0216] Non-cleavable linkers remain inert in common chemical and enzymatic environments in the body. Non- cleavable linkers include linkers having an amino acid sequence lacking a protease cleavage site.

[0217] In some embodiments, a linker sequence may be a flexible linker sequence. Flexible linker sequences allow for relative movement of the amino acid sequences which are linked by the linker sequence. Flexible linkers are known to the skilled person, and several are identified in Chen etal., Adv Drug Deliv Rev (2013) 65(10): 1357-1369. Flexible linker sequences often comprise high proportions of glycine and / or serine residues. In some embodiments, the flexible linker comprises, or consists of, an amino acid sequence according to SEQ ID NO: 34 or SEQ ID NO: 35. In some embodiments, the flexible linker comprises or consists of an amino acid sequence according to any of SEQ ID NOs: 37-40. In some embodiments, the flexible linker comprises or consists of an amino acid sequence according to SEQ ID NO: 71.

[0218] In some embodiments, the linker sequence between the obesity-related peptide moiety and the myostatin pathway inhibitor moiety comprises or consists of a rigid linker. In some embodiments, the linker comprises, or consists of, an amino acid sequence according to any of SEQ ID NOs: 41-45. In some embodiments, the rigid linker comprises or consists of an amino acid sequence according to SEQ ID NO: 68, SEQ ID NO: 69 or SEQ ID NO: 70.

[0219] In some embodiments, the linker sequence comprises at least one glycine residue and / or at least one serine residue. In some embodiments, the linker sequence comprises, or consists of, glycine and serine residues. In some embodiments, the linker sequence has the structure: (GxS)n or (GxS)nGm; wherein G = glycine, S = serine, x = 3 or 4, n = 2, 3, 4, 5 or 6, and m = 0, 1 , 2 or 3. In some embodiments, the linker sequence comprises one or more (e.g. 1 , 2, 3, 4, 5 or 6) copies (e.g. in tandem) of the sequence motif G4S. In some embodiments, the linker sequence comprises or consists of (G4S)4 or (G4S)e. In some embodiments, the linker is a glycine and serine rich linker that comprises or consists of an amino acid sequence according to SEQ ID NO: 75. In some embodiments, the linker confers protease resistance. In some embodiments, the linker that confers protease resistance is a linker that comprises or consists of an amino acid sequence according to SEQ ID NO: 72.

[0220] In some embodiments, the linker confers enhanced solubility. In some embodiments, the linker that confers enhanced solubility is a linker that comprises or consists of an amino acid sequence according to SEQ ID NO: 74 or SEQ ID NO:71 .

[0221] In some embodiments, the linker confers half-life extension via glycosylation. In some embodiments, the linker that confers half-life extension via glycosylation is a linker that comprises or consists of an amino acid sequence according to SEQ ID NO: 73.

[0222] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule, and the obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety peptide or polypeptide) is connected to the antigen-binding molecule via a linker (e.g. a protease-cleavable linker).

[0223] In some embodiments, the antigen-binding molecule is a single polypeptide (e.g. a scFv) and the obesity- related peptide moiety is connected to the antigen-binding polypeptide via a linker. In such cases, the fusion molecule can form a single polypeptide comprising the obesity-related peptide moiety domain, a linker and a myostatin pathway inhibition domain which is an antigen-binding polypeptide. In some embodiments, the antigen-binding molecule is an antigen-binding polypeptide complex, and the obesity- related peptide moiety (e.g. a GLP-1 receptor agonist moiety) is fused to one or more constituent polypeptides of the antigen-binding polypeptide complex via a linker. For example, the antigen-binding polypeptide complex may be an IgG type molecule having the usual arrangement of disulfide bonds preserved between the heavy and light chains of the molecule. In such embodiments, the obesity-related peptide moiety may be connected via a linker to (i) a polypeptide comprising a VH region, or (ii) a polypeptide comprising a VL region. For example, the obesity-related peptide moiety may be connected via a linker to (i) a polypeptide comprising a VH region, CH1 region, CH2 region and CH3 region or (ii) a polypeptide comprising a VL region and a CH1 region.

[0224] The fusion molecules of the present disclosure may additionally comprise further amino acids or sequences of amino acids. For example, the fusion molecules of the present disclosure may comprise amino acid sequence(s) to facilitate expression, folding, trafficking, processing, purification or detection of the antigen-binding molecule / polypeptide.

[0225] Chemical Conjugation

[0226] In some embodiments, the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is connected to the myostatin pathway inhibitor moiety via chemical conjugation. In other words, in some embodiments, the myostatin pathway inhibitor moiety is an antibody and the fusion molecule is an antibody-peptide conjugate. Obesity-related peptide moieties (e.g. GLP-1 receptor agonists) according to the present disclosure may be conjugated to myostatin pathway inhibitors according to the present disclosure for the production of fusion molecules according to the present disclosure by any suitable techniques, which are well known to the skilled person and routinely employed in the art.

[0227] Antibody-drug conjugates (ADCs) generally comprise three main components: an antibody, a chemical linker and a payload. General methods for the conjugation of antibodies to linker-payload moieties are described e.g. in Tsuchikama and An, Protein Cell. (2018) 9(1): 33-46 (hereby incorporated by reference in its entirety). It will be appreciated that the fusion molecules of the present disclosure the payload is a peptide ( / .e. an obesity-related peptide moiety such as a GLP-1 receptor agonist peptide or a GIP antagonist peptide). The term “chemical linker” as used herein refers to the component linking the antibody and the peptide. That is, the chemical linker according to the present invention refers to the component of the conjugate of the present invention that connects the myostatin pathway inhibitor antibody and the obesity-related peptide moiety.

[0228] In some embodiments, the chemical linker according to the present invention further comprises a spacer. Commonly employed spacer moieties include hemiaminal groups, PEG groups, polar acyl sulfamide groups, polar carbamoyl sulfamide groups and HydraSpace (described e.g. in Verkade et al., Antibodies (Basel) (2018) 7(1):12).

[0229] Cysteine Conjugation

[0230] In some embodiments, the obesity-related peptide moiety is connected to the myostatin pathway inhibitor moiety via cysteine-based conjugation.

[0231] In such embodiments, a cysteine residue is introduced into the antibody for conjugation with chemical groups, such as the maleimide group. In some embodiments, the myostatin pathway inhibitor antibody comprises a cysteine residue for conjugation with an obesity-related peptide moiety (via a chemical linker).

[0232] In some embodiments, the chemical linker comprises a thiol-reactive group. In some embodiments, the chemical linker is coupled to the antibody via reaction between cysteine residues in the antibody and a thiol-reactive functional group in the chemical linker. In some embodiments the chemical linker comprises a maleimide group. In some embodiments, the chemical linker comprises a maleimidocaproyl group. In such embodiments, the maleimidocaproyl group is reacted with a thiol group of a cysteine residue of the antibody to form a sulphur-carbon bond, thereby effecting linkage of the chemical linker to the antibody.

[0233] In some embodiments the chemical linker comprises a halo-acetamide group (e.g. a bromo-acetamide, iodo- acetamide or chloro-acetamide group). In some embodiments the chemical linker comprises a bromo-acetamide group.

[0234] A halo-acetamide group exhibits slower kinetics compared to a maleimide group. Therefore, chemical linkers comprising such reactive groups will be more stable in vivo (and in serum) compared with maleimide groups. It will be appreciated that the linker conjugation chemistry can be adjusted to provide control of the drug release ( / .e. Maleimide- linker is less stable and therefore fast release in vivo while bromoacetamide conjugation is far more stable in vivo and therefore gives slow release).

[0235] Enzymatic Conjugation

[0236] In some embodiments, the obesity-related peptide moiety is chemically conjugated to the myostatin pathway inhibitor moiety via enzymatic conjugation. Enzymes can be used to achieve site-selective antibody modification due to their high specificity and mild reaction conditions. Enzymes can either directly attach a payload to a specific amino acid sequence or introduce a reactive functionality on the antibody that can be further functionalised with the desired payload. In some such embodiments, the peptide sequence for enzymatic recognition is genetically incorporated into the amino acid sequence of the antibody.

[0237] Exemplary fusion molecule structures

[0238] A first exemplary fusion molecule design according to the present disclosure is shown in Figure 1 . In some embodiments, provided herein are fusion molecules according to Figure 1.

[0239] In some embodiments a fusion molecule according to the present disclosure comprises: a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide, a myostatin pathway inhibitor moiety antigen-binding molecule, optionally an obesity-related peptide moiety, and optionally a muscle-preserving moiety.

[0240] In some embodiments a fusion molecule according to the present disclosure comprises: a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide, a myostatin pathway inhibitor moiety antigen-binding molecule, optionally an obesity-related peptide moiety, and optionally a muscle-preserving moiety; wherein the GLP-1 receptor agonist peptide is fused to the myostatin pathway inhibitor antigenbinding molecule via a linker, optionally a protease-cleavable linker.

[0241] Fusion molecules of the present disclosure may comprise a GLP-1 receptor agonist moiety oriented to retain GLP-1 receptor agonist functionality. As used herein, the term ‘orientation’ refers to the orientation relative to the other components of the fusion molecule (e.g. the orientation of the GLP-1 receptor agonist moiety relative to the myostatin pathway inhibitor moiety). For example, when the GLP-1 receptor agonist moiety is a peptide, the N or the C-terminus of the GLP-1 receptor agonist moiety peptide may be fused to the myostatin pathway inhibitor moiety. In some embodiments, the N-terminus of a GLP-1 receptor agonist moiety peptide is fused to the myostatin pathway inhibitor moiety. In such embodiments, the GLP- 1 receptor agonist moiety peptide may be connected via a cleavable linker in order to retain functionality of the GLP-1 receptor agonist moiety peptide. GLP-1 receptor agonist peptides known in the art require a vacant N-terminus to be fully functional. Therefore, fusion molecules encompassing GLP-1 receptor agonist moiety peptides are preferably designed to ensure that GLP-1 has a free N-terminus. Accordingly, in some preferred embodiments, the C-terminus of a GLP-1 receptor agonist peptide is fused to the myostatin pathway inhibitor moiety (e.g. a myostatin pathway inhibitor peptide or polypeptide). In such embodiments the C-terminus of a GLP-1 receptor agonist moiety peptide may be directly connected to the myostatin pathway inhibitor moiety or connected via a linker.

[0242] It will be appreciated that fusion molecules must be designed to retain the functionality of the myostatin pathway inhibitor moiety. For example, when the myostatin pathway inhibitor moiety is a peptide or polypeptide, the obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety peptide) may be fused to the N or the C-terminus of the myostatin pathway inhibitor moiety peptide or polypeptide.

[0243] In some embodiments, the myostatin pathway inhibitor moiety is a peptide or polypeptide, and the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the N-terminus of the myostatin pathway inhibitor moiety. In some embodiments, the C-terminus of the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the N-terminus of the myostatin pathway inhibitor peptide or polypeptide. In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, a polypeptide complex (e.g. an antibody) and the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the N-terminus of a constituent polypeptide of the polypeptide complex.

[0244] In some embodiments, the myostatin pathway inhibitor moiety is a peptide or polypeptide, and the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the C-terminus of the myostatin pathway inhibitor moiety. In some such embodiments, the C-terminus of the obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the C-terminus of the myostatin pathway inhibitor moiety, optionally via a linker (e.g. a cleavable linker). In some embodiments, the myostatin pathway inhibitor moiety is, or comprises, a polypeptide complex (e.g. an antibody) and the obesity- related peptide moiety (e.g. GLP-1 receptor agonist moiety) is fused to the C-terminus of a constituent polypeptide of the polypeptide complex.

[0245] Antibody Fusions

[0246] N-terminal heavy and / or light chain fusions

[0247] An exemplary fusion molecule according to the present disclosure is shown in Figure 1 .

[0248] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain (e.g. an IgG type antigen-binding molecule), and the obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist) is fused to the N-terminus of the antibody heavy chain. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain, and the C-terminus of an obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain.

[0249] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0250] (i) a first polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist), wherein the C-terminus of the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain, and optionally a muscle-preserving moiety, wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain; and

[0251] (ii) a second polypeptide, comprising, or consisting of: the antibody light chain of the antibody that binds to a myostatin pathway protein.

[0252] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0253] (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: an obesity-related peptide moiety, a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein, and optionally a muscle-preserving moiety; and

[0254] (ii) a second polypeptide comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein.

[0255] In some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0256] (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: a GLP-1 receptor agonist moiety, a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein; and

[0257] (ii) a second polypeptide, comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein.

[0258] In any of the embodiments disclosed herein, the fusion molecule may additionally comprise a musclepreserving moiety as described herein.

[0259] Further exemplary fusion molecules according to the present disclosure are shown in Figure 14.

[0260] In some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0261] (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: a GLP-1 receptor agonist moiety, a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein, and optionally a muscle-preserving moiety (e.g. an anti-activin receptor scFv); and

[0262] (ii) a second polypeptide, comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain, and the obesity-related peptide moiety is a GIP receptor agonist (e.g. GIP1-42 or GIP 1-30), wherein the GIP receptor agonist is fused to the N-terminus of the antibody heavy chain. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain, and the C-terminus of the GIP receptor agonist is fused to the N- terminus of the antibody heavy chain.

[0263] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0264] (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: a GIP receptor agonist or antagonist moiety (e.g. GIP1-42 or GIP 1-30), a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein, and optionally a muscle-preserving moiety (e.g. an anti-activin receptor scFv); and

[0265] (ii) a second polypeptide, comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein.

[0266] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain, and the obesity-related peptide moiety is a GCG receptor agonist, wherein the GCG receptor agonist is fused to the N-terminus of the antibody heavy chain. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain, and the C-terminus of the GCG receptor agonist is fused to the N-terminus of the antibody heavy chain.

[0267] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0268] (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: a GCG receptor agonist moiety, a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein, and optionally a muscle-preserving moiety (e.g. an anti-activin receptor scFv); and

[0269] (ii) a second polypeptide, comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein.

[0270] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain, and the obesity-related peptide moiety is a GHRH receptor agonist (e.g. GHRH or GHRH 1-30), wherein the GHRH receptor agonist is fused to the N-terminus of the antibody heavy chain. In some embodiments, the myostatin pathway inhibitor moiety is an antigenbinding molecule that comprises an antibody heavy chain, and the C-terminus of the GHRH receptor agonist is fused to the N-terminus of the antibody heavy chain.

[0271] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0272] (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: a GHRH receptor agonist moiety (e.g. GHRH or GHRH 1-30), a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein, and optionally a muscle-preserving moiety (e.g. an anti-activin receptor scFv); and

[0273] (ii) a second polypeptide, comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein.

[0274] In some embodiments, a fusion molecule according to the present disclosure comprises:

[0275] (i) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide having at least 70% sequence identity to SEQ ID NO: 1 or 2;

[0276] (ii) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an IgG-type antigen binding molecule;

[0277] (iii) optionally an obesity-related peptide moiety; and

[0278] (iv) optionally a muscle-preserving moiety; wherein the C-terminus of the GLP-1 receptor agonist moiety peptide is fused to the N-terminus of the heavy chain of the myostatin pathway inhibitor moiety IgG-type antigen binding molecule via a linker, optionally a furin-cleavable linker.

[0279] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody light chain (e.g. an IgG type antigen-binding molecule), and the obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist) is fused to the N-terminus of the antibody light chain. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody light chain, and the C-terminus of an obesity-related peptide moiety is fused to the N-terminus of the antibody light chain.

[0280] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0281] (i) a first polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein; and

[0282] (ii) a second polypeptide, comprising, or consisting of: an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist) and the antibody light chain of the antibody that binds to a myostatin pathway protein, wherein the C-terminus of the obesity-related peptide moiety is fused to the N-terminus of the antibody light chain.

[0283] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0284] (i) a first polypeptide comprising from N- to C-terminus: a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein; and

[0285] (ii) a second polypeptide, comprising from N- to C-terminus: an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety), a VL and a CL of the antibody that binds to a myostatin pathway protein. In some embodiments, a fusion molecule according to the present disclosure comprises:

[0286] (i) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide having at least 70% sequence identity to SEQ ID NO: 1 or 2;

[0287] (ii) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an IgG-type antigen binding molecule;

[0288] (iii) optionally an obesity-related peptide moiety; and

[0289] (iv) optionally a muscle-preserving moiety; wherein the C-terminus of the GLP-1 receptor agonist moiety peptide is fused to the N-terminus of the light chain of the myostatin pathway inhibitor moiety IgG-type antigen binding molecule via a linker, optionally a furin-cleavable linker.

[0290] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain and an antibody light chain (e.g. an IgG type antigen-binding molecule), and an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety) is fused to the N-terminus of the antibody heavy chain and to the N-terminus of the antibody light chain. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain and an antibody light chain, and the C-terminus of an obesity-related peptide moiety is fused to the N- terminus of the antibody heavy chain and the C-terminus of an obesity-related peptide moiety is fused to the N-terminus of the antibody light chain.

[0291] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising:

[0292] (i) a first polypeptide, comprising: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and a first obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist), wherein the C-terminus of the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain; and

[0293] (ii) a second polypeptide, comprising a second obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist) and the antibody light chain of the antibody that binds to a myostatin pathway protein, wherein the C-terminus of the second obesity-related peptide moiety is fused to the N-terminus of the antibody light chain.

[0294] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising:

[0295] (i) a first polypeptide comprising from N- to C-terminus: a GLP-1 receptor agonist moiety, a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein, and

[0296] (ii) a second polypeptide, comprising from N- to C-terminus: a GLP-1 receptor agonist moiety, a VL and a CL of the antibody that binds to a myostatin pathway protein. In the embodiment described above, the GLP-1 receptor agonist moiety fused to either the heavy chain or the light chain (in other words the GLP-1 receptor agonist moiety of the first or second polypeptide) may be substituted for an obesity-related peptide moiety disclosed herein. In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising:

[0297] (i) a first polypeptide comprising from N- to C-terminus: a first obesity-related peptide moiety, a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein; and

[0298] (ii) a second polypeptide, comprising from N- to C-terminus: a second obesity-related peptide moiety, a VL and a CL of the antibody that binds to a myostatin pathway protein.

[0299] It will be appreciated that in some such embodiments, the myostatin pathway inhibitor moiety is an antibody comprising an antibody heavy chain and an antibody light chain, and GLP-1 receptor agonist moiety is a peptide, and

[0300] (i) the C-terminus of a GLP-1 receptor agonist moiety is fused to the N-terminus of the antibody heavy chain and a second obesity-related peptide moiety is fused to the N-terminus of the antibody light chain; or

[0301] (ii) the C-terminus of a GLP-1 receptor agonist moiety is fused to the N-terminus of the antibody light chain and a second obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain.

[0302] In some embodiments, a fusion molecule according to the present disclosure comprises:

[0303] (i) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide having at least 70% sequence identity to SEQ ID NO: 1 or 2;

[0304] (ii) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an IgG-type antigen binding molecule;

[0305] (iii) optionally an obesity-related peptide moiety; and

[0306] (iv) optionally a muscle-preserving moiety; wherein the C-terminus of the GLP-1 receptor agonist moiety is fused to the N-terminus of the antibody heavy and light chains of the myostatin pathway inhibitor moiety via a linker, optionally a furin- cleavable linker.

[0307] C-terminal light chain fusions

[0308] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody light chain (e.g. an IgG type antigen-binding molecule), and the obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist) is fused to the C-terminus of the antibody light chain. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody light chain, and the N-terminus of an obesity-related peptide moiety is fused to the C-terminus of the antibody light chain.

[0309] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of: (i) a first polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein; and

[0310] (ii) a second polypeptide, comprising, or consisting of: an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety) and the antibody light chain of the antibody that binds to a myostatin pathway protein, wherein the N-terminus of the obesity-related peptide moiety (e.g. the N-terminus of the GLP-1 receptor agonist moiety) is fused to the C-terminus of the antibody light chain.

[0311] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0312] (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein; and

[0313] (ii) a second polypeptide, comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein, and an obesity-related peptide moiety, wherein the N- terminus of the obesity-related peptide moiety is fused to the C-terminus of the CL.

[0314] In some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0315] (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein, and optionally a musclepreserving moiety (e.g. an anti-activin receptor scFv); and

[0316] (ii) a second polypeptide, comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein, and a GLP-1 receptor agonist moiety, wherein the N- terminus of a GLP-1 receptor agonist peptide is fused to the C-terminus of the CL.

[0317] In such embodiments, the N-terminus of the GLP-1 receptor agonist remains unexposed, thus allowing higher dosing of the fusion molecule without triggering adverse reactions.

[0318] In some embodiments, a fusion molecule according to the present disclosure comprises:

[0319] (i) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide (e.g. a GLP-1 / GIP or GLP-1 / GCG receptor co-agonist peptide);

[0320] (ii) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an IgG-type antigen binding molecule (e.g. an anti-myostatin antibody);

[0321] (iii) optionally an obesity-related peptide moiety; and

[0322] (iv) optionally a muscle-preserving moiety (e.g. an anti-activin A scFv or nanobody); wherein the N-terminus of the GLP-1 receptor agonist moiety is fused to the C-terminus of the light chain of the myostatin pathway inhibitor moiety via a linker, optionally a protease-cleavable linker.

[0323] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain, and the obesity-related peptide moiety is an amylin receptor agonist, wherein the amylin receptor agonist is fused to the C-terminus of the antibody light chain.

[0324] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of: (i) a first polypeptide comprising, or consisting of, from N- to C-terminus: a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein, and optionally a musclepreserving moiety (e.g. an anti-activin receptor scFv); and

[0325] (ii) a second polypeptide, comprising, or consisting of, from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein, and an amylin receptor agonist moiety, wherein the N- terminus of the amylin receptor agonist moiety is fused to the C-terminus of the CL.

[0326] N-terminal heavy chain and C-terminal light chain fusions

[0327] In some embodiments, the myostatin pathway inhibitor moiety is an antibody comprising an antibody heavy chain and an antibody light chain (e.g. an IgG type antigen-binding molecule), and a GLP-1 receptor agonist moiety is fused to the N-terminus of the antibody heavy chain and to the C-terminus of the antibody light chain. In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0328] (i) a first polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and a GLP-1 receptor agonist moiety, wherein the C-terminus of the GLP-1 receptor agonist moiety is fused to the N-terminus of the antibody heavy chain; and

[0329] (ii) a second polypeptide, comprising, or consisting of: a GLP-1 receptor agonist moiety and the antibody light chain of the antibody that binds to a myostatin pathway protein, wherein the N-terminus of the GLP-1 receptor agonist moiety is fused to the C-terminus of the antibody light chain.

[0330] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising:

[0331] (i) a first polypeptide comprising from N- to C-terminus: a GLP-1 receptor agonist moiety, a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein; and

[0332] (ii) a second polypeptide, comprising from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein, and a GLP-1 receptor agonist moiety, wherein the N-terminus of a GLP-1 receptor agonist peptide is fused to the C-terminus of the CL.

[0333] A further exemplary fusion molecule design according to the present disclosure is shown in Figure 10. In some such embodiments, the obesity-related peptide moiety is fused to the N-terminus of the heavy chain of the myostatin pathway inhibitor moiety via a linker, optionally a protease-cleavable linker. It will therefore be appreciated that in the embodiment described in the 2 paragraphs above, the GLP-1 receptor agonist moiety fused to the N-terminus of the antibody heavy chain or the C-terminus of the light chain (in other words the GLP-1 receptor agonist moiety of the first or second polypeptide) may be substituted for an obesity-related peptide moiety as described herein ( / .e. an obesity-related peptide moiety other than a GLP-1 agonist moiety).

[0334] Accordingly, in some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain and an antibody light chain (e.g. an IgG type antigenbinding molecule), wherein an obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain or the C-terminus of the light chain. In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0335] (i) a first polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and a first obesity-related peptide moiety, wherein the C-terminus of the first obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain; and

[0336] (ii) a second polypeptide, comprising, or consisting of: a second obesity-related peptide moiety and the antibody light chain of the antibody that binds to a myostatin pathway protein, wherein the N-terminus of the second obesity-related peptide moiety is fused to the C-terminus of the antibody light chain.

[0337] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising:

[0338] (i) a first polypeptide comprising from N- to C-terminus: a first obesity-related peptide moiety, a VH, CH1 region, CH2 region and CH3 region of an antibody that binds to a myostatin pathway protein; and

[0339] (ii) a second polypeptide, comprising from N- to C-terminus: a VL and a CL of the antibody that binds to a myostatin pathway protein, and a second obesity-related peptide moiety, wherein the N-terminus of the second obesity-related peptide moiety is fused to the C-terminus of the CL.

[0340] In some preferred embodiments, the GLP-1 receptor agonist moiety fused to the N-terminus of the antibody heavy chain of the myostatin pathway inhibitor moiety is substituted for an alternative obesity- related peptide moiety. In other words, the fusion molecule comprises an obesity-related peptide moiety (e.g. a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon (GCG) receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist) fused to the N-terminus of the antibody heavy chain of the myostatin pathway inhibitor moiety. Accordingly, in some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain and an antibody light chain (e.g. an IgG type antigenbinding molecule), wherein an obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain and a GLP-1 receptor agonist moiety is fused to the C-terminus of the antibody light chain. In other words, in some embodiments the fusion molecule is a polypeptide complex comprising:

[0341] (i) a first polypeptide comprising, or consisting of, an antibody heavy chain and an obesity-related peptide moiety, wherein the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain; and

[0342] (ii) a second polypeptide comprising, or consisting of, an antibody light chain and a GLP-1 receptor agonist peptide, wherein the N-terminus of a GLP-1 receptor agonist peptide is fused to the C-terminus of the antibody light chain.

[0343] In other words, in some embodiments the fusion molecule is a polypeptide complex comprising, or consisting of:

[0344] (i) a first polypeptide comprising from N- to C-terminus an obesity-related peptide moiety, a VH, CH1 region, CH2 region and CH3 region; and

[0345] (ii) a second polypeptide comprises from N- to C-terminus a VL, a CL and a GLP-1 receptor agonist peptide, wherein the N-terminus of a GLP-1 receptor agonist peptide is fused to the C-terminus of the CL. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain and an antibody light chain, and

[0346] (i) the C-terminus of a GLP-1 receptor agonist moiety is fused to the N-terminus of the antibody heavy chain and an obesity-related peptide moiety is fused to the C-terminus of the antibody light chain; or

[0347] (ii) the N-terminus of a GLP-1 receptor agonist moiety is fused to the C-terminus of the antibody light chain and an obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain.

[0348] In any of such embodiments, the fusion molecule may further comprise a muscle-preserving moiety (e.g. any of the muscle-preserving moieties described herein). In any of the exemplary embodiments described hereinabove, the fusion molecule may further comprise a muscle-preserving moiety fused to the antibody heavy chain. For example, in some embodiments a muscle-preserving moiety (e.g. comprising an anti- activin A scFv or nanobody) is fused to the C-terminus of the antibody heavy chain.

[0349] Accordingly, in some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule comprising an antibody heavy chain and an antibody light chain, wherein an obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain, a GLP-1 receptor agonist moiety is fused the C-terminus of the antibody light chain and a muscle-preserving moiety (e.g. comprising an anti- activin A scFv or nanobody) is fused to the C-terminus of the antibody heavy chain. In other words, in some embodiments the fusion molecule is a polypeptide complex comprising, or consisting of:

[0350] (i) a first polypeptide comprising from N- to C-terminus: an obesity-related peptide moiety, the antibody heavy chain of an antibody that binds to a myostatin pathway protein and a muscle-preserving moiety; and

[0351] (ii) a second polypeptide comprising from N- to C-terminus: the antibody light chain of the antibody that binds to a myostatin pathway protein and a GLP-1 receptor agonist peptide, wherein the N-terminus of a GLP-1 receptor agonist peptide is fused to the C-terminus of the antibody light chain.

[0352] In some embodiments, the fusion molecule is a polypeptide complex comprising:

[0353] (i) a first polypeptide comprising from N- to C-terminus: an antibody light chain of an antibody that binds to a myostatin pathway protein (e.g. consisting of a VL and CL region) and a GLP-1 receptor agonist moiety;

[0354] (ii) a second polypeptide comprising from N- to C-terminus: an obesity-related peptide moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein (e.g. consisting of a VH, CH1 , CH2 and CH3 region) and a muscle-preserving moiety;

[0355] (iii) a third polypeptide comprising from N- to C-terminus: an obesity-related peptide moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein and a muscle-preserving moiety; and

[0356] (iv) a fourth polypeptide comprising from N- to C-terminus: an antibody light chain of the antibody that binds to a myostatin pathway protein and a GLP-1 receptor agonist moiety.

[0357] In some embodiments the fusion molecule is a polypeptide complex comprising a fusion of a GLP-1 receptor agonist moiety and a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an IgG type antigen binding molecule, wherein the GLP-1 receptor agonist moiety is a peptide having a length of 25-31 amino acids and has 70% sequence identity to an amino acid sequence selected from SEQ ID NO: 1 or 2, wherein the polypeptide complex comprises:

[0358] (i) a first polypeptide comprising a GLP-1 receptor agonist moiety and an antibody heavy chain, wherein the C-terminus of the GLP-1 receptor agonist peptide is fused to the N-terminus of the antibody heavy chain, and a second polypeptide comprising an antibody light chain; or

[0359] (ii) a first polypeptide comprising a GLP-1 receptor agonist moiety and an antibody light chain, wherein the C-terminus of the GLP-1 receptor agonist peptide is fused to the N-terminus of the antibody light chain, and a second polypeptide comprising an antibody heavy chain; or

[0360] (iii) a first polypeptide comprising a GLP-1 receptor agonist moiety and an antibody heavy chain, wherein the C-terminus of the GLP-1 receptor agonist peptide is fused to the N-terminus of the antibody heavy chain, and a second polypeptide comprising a GLP-1 receptor agonist moiety and an antibody light chain, wherein the C-terminus of the GLP-1 receptor agonist peptide is fused to the N-terminus of the antibody light chain; or

[0361] (iv) a first polypeptide comprising a GLP-1 receptor agonist moiety and an antibody light chain, wherein the N-terminus of GLP-1 receptor agonist peptide is fused to the C- terminus of the light chain, and a second polypeptide comprising an antibody heavy chain; or

[0362] (v) a first polypeptide comprising a GLP-1 receptor agonist peptide or an obesity-related peptide moiety, and an antibody heavy chain, wherein the C-terminus of the GLP-1 receptor agonist peptide or the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain, and a second polypeptide comprising a GLP-1 receptor agonist moiety and an antibody light chain, wherein the N- terminus of the GLP-1 receptor agonist peptide is fused to the C-terminus of the light chain; wherein in any of (i) to (v) above, the GLP-1 receptor agonist moiety is fused to the myostatin pathway inhibitor moiety by a protease cleavable linker, optionally a furin-cleavable linker (e.g. a linker having an amino acid sequence selected from any one of SEQ ID NOs: 26-30).

[0363] Asymmetric Fusion Molecules

[0364] In some embodiments, fusion molecules according to the present disclosure are provided with an Fc region comprising a mutation that promotes association of the Fc region (e.g. paired substitutions in the CH3 regions of the Fc region according to one of the following formats, as shown in Table 1 of Ha et al., Front. Immnol (2016) 7:394: KiH, KiHs-s, HA-TF, ZW1 , 7.8.60, DD-KK, EW-RVT, EW-RVTS-S, SEED or A107). Such fusion molecules are described herein as ‘asymmetric’ because they comprise non-identical Fc regions (e.g. comprising antibody heavy chains comprising non-identical Fc regions).

[0365] Inclusion of a mutation that promotes association of the Fc region facilitates fusing different (non- identical) obesity-related peptide moieties to each of the two heavy chains of the antigen binding molecule. Accordingly, asymmetric fusion molecules as described herein may comprise non-identical obesity-related peptide moieties fused to each of the constituent antibody heavy chains of the fusion molecule. It will be appreciated that in some such embodiments, the fusion molecule comprises an antibody heavy chain (e.g. the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises an antibody heavy chain) and the Fc region of the antibody heavy chain comprises the mutation that promotes association of the Fc region. In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises a first antibody heavy chain comprising a mutation that promotes association of the Fc region and a second antibody heavy chain comprising a mutation that promotes association of the Fc region, wherein a first obesity-related peptide moiety is fused to the N-terminus of the first antibody heavy chain and a second obesity-related peptide moiety is fused to the N-terminus of the second antibody heavy chain, wherein the first and second obesity-related peptide moiety are independently selected from a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist. It will be appreciated that the mutations of the first and second antibody heavy chain together promote association of the first and second antibody heavy chains.

[0366] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0367] (i) a first polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist), wherein the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain, and optionally a muscle-preserving moiety, wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain;

[0368] (i) a second polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and an obesity-related peptide moiety, wherein the obesity- related peptide moiety is fused to the N-terminus of the antibody heavy chain, and optionally a musclepreserving moiety, wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain; and

[0369] (iii) a third polypeptide, comprising, or consisting of: the antibody light chain of the antibody that binds to a myostatin pathway protein; wherein the antibody heavy chains of the first polypeptide and second polypeptide comprise paired substitutions in the CH3 regions of the Fc region according to one of the following formats: KiH, KiHs-s, HA-TF, ZW1 , 7.8.60, DD-KK, EW-RVT, EW-RVTS-S, SEED or A107.

[0370] In some embodiments, the fusion molecule is a polypeptide complex comprising:

[0371] (i) a first polypeptide comprising from N- to C-terminus: an obesity-related peptide moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein (e.g. consisting of a VH, CH1 , CH2 and CH3 region), and optionally a muscle-preserving moiety (e.g. a scFv);

[0372] (ii) a second polypeptide comprising from N- to C-terminus: an obesity-related peptide moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein, and optionally a musclepreserving moiety (e.g. a scFv); and

[0373] (iii) a third polypeptide comprising from N- to C-terminus: an antibody light chain of an antibody that binds to a myostatin pathway protein (e.g. consisting of a VL and CL region); wherein the antibody heavy chains of the first polypeptide and second polypeptide comprise paired substitutions in the CH3 regions of the Fc region according to one of the following formats: KiH, KiHs-s, HA-TF, ZW1 , 7.8.60, DD-KK, EW-RVT, EW-RVTS-S, SEED or A107.

[0374] In some embodiments, fusion molecules according to the present disclosure are provided with an Fc region comprising the ‘knob-into-hole’ or ‘KiH’ modification, e.g. as described hereinabove. In such embodiments, one of the CH3 regions of the Fc region comprises a ‘knob’ modification, and the other CH3 region comprises a ‘hole’ modification. The ‘knob’ and ‘hole’ modifications are positioned within the respective CH3 regions so that the ‘knob’ can be positioned in the ‘hole’ in order to promote heterodimerisation (and inhibit homodimerisation) of the constituent polypeptides of the fusion molecule and / or stabilise heterodimers.

[0375] In some embodiments, the myostatin pathway inhibitor moiety is an antigen-binding molecule that comprises a first antibody heavy chain comprising a ‘knob’ modification and a second antibody heavy chain comprising a ‘hole modification, wherein a first obesity-related peptide moiety is fused to the N- terminus of the first antibody heavy chain and a second obesity-related peptide moiety is fused to the N- terminus of the second antibody heavy chain, wherein the first and second obesity-related peptide moiety are independently selected from a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist.

[0376] In other words, in some embodiments, the fusion molecule is a polypeptide complex comprising, or consisting of:

[0377] (i) a first polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist), wherein the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain, and optionally a muscle-preserving moiety, wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain;

[0378] (i) a second polypeptide, comprising, or consisting of: the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and an obesity-related peptide moiety, wherein the obesity- related peptide moiety is fused to the N-terminus of the antibody heavy chain, and optionally a musclepreserving moiety, wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain; and

[0379] (iii) a third polypeptide, comprising, or consisting of: the antibody light chain of the antibody that binds to a myostatin pathway protein; wherein the antibody heavy chain of the first polypeptide comprises a ‘knob’ modification and the antibody heavy chain of the second polypeptide comprises a ‘hole’ modification.

[0380] In some embodiments, the fusion molecule is a polypeptide complex comprising: (i) a first polypeptide comprising from N- to C-terminus: an obesity-related peptide moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein (e.g. consisting of a VH, CH1 , CH2 and CH3 region), and optionally a muscle-preserving moiety (e.g. a scFv);

[0381] (ii) a second polypeptide comprising from N- to C-terminus: an obesity-related peptide moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein, and optionally a musclepreserving moiety (e.g. a scFv); and

[0382] (iii) a third polypeptide comprising from N- to C-terminus: an antibody light chain of an antibody that binds to a myostatin pathway protein (e.g. consisting of a VL and CL region); wherein the antibody heavy chain of the first polypeptide comprises a ‘knob’ modification and the antibody heavy chain of the second polypeptide comprises a ‘hole’ modification.

[0383] In some embodiments, the fusion molecule is a polypeptide complex comprising:

[0384] (i) a first polypeptide comprising from N- to C-terminus: a GLP-1 receptor agonist moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein (e.g. consisting of a VH, CH1 , CH2 and CH3 region), and optionally a muscle-preserving moiety (e.g. an anti-activin receptor 2B scFv); and

[0385] (ii) a second polypeptide comprising from N- to C-terminus: a GIP receptor agonist moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein, and optionally a musclepreserving moiety (e.g. an anti-activin receptor 2B scFv); and

[0386] (iii) a third polypeptide comprising from N- to C-terminus: an antibody light chain of an antibody that binds to a myostatin pathway protein (e.g. consisting of a VL and CL region); wherein the antibody heavy chain of the first polypeptide comprises a ‘knob’ modification and the antibody heavy chain of the second polypeptide comprises a ‘hole’ modification.

[0387] In some embodiments, the fusion molecule is a polypeptide complex comprising:

[0388] (i) a first polypeptide comprising from N- to C-terminus: a GLP-1 receptor agonist moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein (e.g. consisting of a VH, CH1 , CH2 and CH3 region), and optionally a muscle-preserving moiety (e.g. an anti-activin receptor 2B scFv); and

[0389] (ii) a second polypeptide comprising from N- to C-terminus: a GHRH receptor agonist moiety, an antibody heavy chain of the antibody that binds to a myostatin pathway protein, and optionally a musclepreserving moiety (e.g. an anti-activin receptor 2B scFv); and

[0390] (iii) a third polypeptide comprising from N- to C-terminus: an antibody light chain of an antibody that binds to a myostatin pathway protein (e.g. consisting of a VL and CL region); wherein the antibody heavy chain of the first polypeptide comprises a ‘knob’ modification and the antibody heavy chain of the second polypeptide comprises a ‘hole’ modification.

[0391] It will be appreciated that in the embodiments described above, the ‘knob’ and ‘hole’ modifications may be swapped. In other words, in the embodiments described in the preceding three paragraphs, the antibody heavy chain of the first polypeptide may comprise a ‘hole’ modification and the antibody heavy chain of the second polypeptide may comprise a ‘knob’ modification. Exemplary Sequences

[0392] In some embodiments, a fusion molecule according to the present disclosure comprises a GLP-1 receptor agonist moiety fused to a bimagrumab heavy chain (e.g. a bimagrumab heavy chain according to SEQ ID NO: 52). In some embodiments, a fusion molecule according to the present disclosure comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 60.

[0393] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a GLP-1 receptor agonist moiety fused to a bimagrumab heavy chain, and (ii) a bimagrumab light chain. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO:

[0394] 60 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 53.

[0395] In some embodiments, a fusion molecule according to the present disclosure comprises a GLP-1 receptor agonist moiety fused to a bimagrumab light chain (e.g. a bimagrumab light chain according to SEQ ID NO: 53). In some embodiments, a fusion molecule according to the present disclosure comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 61.

[0396] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a GLP-1 receptor agonist moiety fused to a bimagrumab light chain, and (ii) a bimagrumab heavy chain. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO:

[0397] 61 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 52.

[0398] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a GLP-1 receptor agonist moiety fused to a bimagrumab heavy chain, and (ii) a GLP-1 receptor agonist moiety fused to a bimagrumab light chain. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 60 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 61. In some embodiments, a fusion molecule according to the present disclosure comprises (i) a GLP-1 receptor agonist moiety fused to a bimagrumab light chain (e.g. a bimagrumab light chain according to SEQ ID NO: 53); and (ii) a Bimagrumab scFv fused to a bimagrumab heavy chain (e.g. a bimagrumab heavy chain according to SEQ ID NO: 52). In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 61 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 62.

[0399] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a GLP-1 receptor agonist moiety fused to the heavy chain of an antibody that binds an activin receptor (e.g. a bimagrumab heavy chain (e.g. a bimagrumab heavy chain according to SEQ ID NO: 52)); and (ii) a Bimagrumab scFv fused to the heavy chain of the antibody that binds an activin receptor. In some embodiments, a fusion molecule according to the present disclosure comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 63. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 63 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 53.

[0400] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, a GLP-1 receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab); and (ii) a second polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 78. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 78 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 77.

[0401] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, a NEP-resistant GLP-1 receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab); and (ii) a second polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 106 or SEQ ID NO: 107. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 106 or SEQ ID NO: 107, and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 77.

[0402] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, a GIP receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab); and (ii) a second polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 79 or SEQ ID NO: 80. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 79 or SEQ ID NO: 80 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 77.

[0403] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, a GCG receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab); and (ii) a second polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 81 . In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 81 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 77.

[0404] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, a GHRH receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab); and (ii) a second polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 82 or SEQ ID NO: 83. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 82 or SEQ ID NO: 83 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 77.

[0405] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab); and (ii) a second polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin and an amylin receptor agonist. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 84. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 76 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 84.

[0406] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, the heavy chain of an antibody that binds myostatin e.g. Landogrozumab), and optionally a muscle preserving moiety (e.g. an anti-activin receptor 2B (e.g. ANB- 012) scFv); (ii) a second polypeptide comprising, or consisting of, the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab), and optionally a muscle preserving moiety (e.g. an anti-activin receptor 2B (e.g. ANB-012) scFv); and (iii) a third polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 101. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 102. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, (i) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 101 ; (ii) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 102; and (iii) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 77. In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, a GLP-1 receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab), and optionally a muscle preserving moiety (e.g. an anti-activin receptor 2B (e.g. ANB-012) scFv); (ii) a second polypeptide comprising, or consisting of, a GIP receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g.

[0407] Landogrozumab), and optionally a muscle preserving moiety (e.g. an anti-activin receptor 2B (e.g. ANB- 012) scFv); and (iii) a third polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 103. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 104. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, (i) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 103; (ii) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 104; and (iii) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 77.

[0408] In some embodiments, a fusion molecule according to the present disclosure comprises (i) a first polypeptide comprising, or consisting of, a GLP-1 receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g. Landogrozumab), and optionally a muscle preserving moiety (e.g. an anti-activin receptor 2B (e.g. ANB-012) scFv); (ii) a second polypeptide comprising, or consisting of, a GHRH receptor agonist moiety and the heavy chain of an antibody that binds myostatin (e.g.

[0409] Landogrozumab), and optionally a muscle preserving moiety (e.g. an anti-activin receptor 2B (e.g. ANB- 012) scFv); and (iii) a third polypeptide comprising, or consisting of, the light chain of the antibody that binds myostatin. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 103. In some embodiments, the fusion molecule comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 105. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, (i) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 103; (ii) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 105; and (iii) an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 77.

[0410] Fc Fusions

[0411] A second exemplary fusion molecule according to the present disclosure comprises Fc-fragments with obesity-related peptide moiety and myostatin pathway inhibitor fusions (e.g. an antibody-derived targetbinding molecule (e.g. a SCFV / VHH)) as shown in Figure 2. In some embodiments, provided herein are fusion molecules according to Figure 2.

[0412] In some embodiments a fusion molecule according to the present disclosure comprises: a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide, an Fc fragment; a myostatin pathway inhibitor moiety; optionally an obesity-related peptide moiety; and optionally a muscle-preserving moiety; wherein the GLP-1 receptor agonist moiety is fused to the Fc fragment via a linker, optionally a furin-cleavable linker.

[0413] In some embodiments, the fusion molecule comprises or consists of a polypeptide complex, comprising:

[0414] (i) a first polypeptide that comprises an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety) fused to a first Fc region; and

[0415] (ii) a second polypeptide comprises an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety) fused to a second Fc region.

[0416] The Fc fragments may comprise a half-life promoting component, (e.g. a knob-in-hole modification) to promote association between a first and second Fc fragment polypeptide. For example, in some embodiments (i) the first Fc fragment comprises a knob modification and the second Fc fragment comprises a hole modification, or (ii) the first Fc fragment comprises a hole modification and the second Fc fragment comprises a knob modification.

[0417] In some embodiments a fusion molecule according to the present disclosure comprises: a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide; an Fc fragment comprising a half-life promoting component, optionally a knob-in-hole modification; a myostatin pathway inhibitor moiety; optionally an obesity-related peptide moiety; and optionally a muscle-preserving moiety; wherein the GLP-1 receptor agonist peptide is fused to the Fc fragment via a linker, optionally a furin-cleavable linker.

[0418] In any of such embodiments, the C-terminus of the GLP-1 receptor agonist moiety may be fused to the Fc fragment. In some embodiments, the fusion molecule comprises or consists of a polypeptide complex, wherein a first polypeptide comprises a GLP-1 receptor agonist peptide fused to a first Fc region and a second polypeptide comprises a GLP-1 receptor agonist peptide fused to a second Fc region, wherein the C- terminus of the GLP-1 receptor agonist peptides is fused to the first and second Fc regions. In some embodiments, the C-terminus of the GLP-1 receptor agonist peptide(s) is fused to the Fc fragment via a linker, optionally a furin-cleavable linker.

[0419] In some embodiments, the C-terminus of the GLP-1 receptor agonist peptide is fused to the N-terminus of the Fc fragment. For example, when the Fc fragment comprises or consists of a CH2 and CH3 region, the C-terminus of the GLP-1 receptor agonist peptide may be fused to the N-terminus of the CH2 region. In some embodiments, the C-terminus of the GLP-1 receptor agonist peptide is fused to the C-terminus of the Fc fragment. For example, when the Fc fragment comprises or consists of a CH2 and CH3 region, the C-terminus of the GLP-1 receptor agonist peptide may be fused to the C-terminus of the CH3 region.

[0420] In some embodiments a fusion molecule according to the present disclosure comprises: a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide; an Fc fragment comprising a half-life promoting component, optionally a knob-in-hole modification; a myostatin pathway inhibitor moiety; optionally an obesity-related peptide moiety; and optionally a muscle-preserving moiety; wherein the C-terminus of the GLP-1 receptor agonist peptide is fused to the N-terminus of the Fc fragment via a linker, optionally a protease-cleavable linker.

[0421] In some embodiments, the fusion molecule comprises or consists of a polypeptide complex, wherein a first polypeptide comprises a GLP-1 receptor agonist moiety fused to a first Fc region and a second polypeptide comprises an obesity-related peptide moiety fused to a second Fc region. In some embodiments, the GLP-1 receptor agonist and / or the obesity-related peptide moiety are fused to the N- terminus of the Fc region of the first and second polypeptide. For example, the GLP-1 receptor agonist and / or the obesity-related peptide moiety may be fused to the CH2 region of the Fc region of the first and second polypeptide respectively. The obesity-related peptide moiety may simultaneously target GLP-1 and another obesity-related target as described herein.

[0422] The Fc fragments may comprise a half-life promoting component, (e.g. a knob-in-hole modification) to promote association between the first and second polypeptide. For example, in some embodiments (i) the first Fc fragment comprises a knob modification and the second Fc fragment comprises a hole modification, or (ii) the first Fc fragment comprises a hole modification and the second Fc fragment comprises a knob modification.

[0423] In some embodiments a fusion molecule according to the present disclosure comprises: a first polypeptide comprising, or consisting of: a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide, fused to a first Fc fragment via a linker, optionally a protease- cleavable linker; a second polypeptide comprising or consisting of an obesity-related peptide moiety fused to a second Fc fragment via a linker, optionally a protease-cleavable linker; a myostatin pathway inhibitor moiety; and optionally a muscle-preserving moiety; optionally wherein (i) the first Fc fragment comprises a knob modification and the second Fc fragment comprises a hole modification, or (ii) the first Fc fragment comprises a hole modification and the second Fc fragment comprises a knob modification.

[0424] In some embodiments a fusion molecule according to the present disclosure comprises: a first polypeptide comprising, or consisting of, a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide, wherein the GLP-1 receptor agonist moiety is C-terminally fused to the CH2 region of a first Fc fragment via a linker, optionally a protease-cleavable linker; a second polypeptide comprising or consisting of an obesity-related peptide moiety fused to the CH2 region of a second Fc fragment via a linker, optionally a protease-cleavable linker; a myostatin pathway inhibitor moiety; and optionally a muscle-preserving moiety; optionally wherein (i) the first Fc fragment comprises a knob modification and the second Fc fragment comprises a hole modification, or (ii) the first Fc fragment comprises a hole modification and the second Fc fragment comprises a knob modification.

[0425] In some embodiments, the fusion molecule comprises or consists of a polypeptide complex, wherein a first polypeptide comprises a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is a peptide or polypeptide, fused to a first Fc region and a second polypeptide comprises a myostatin pathway inhibitor peptide or polypeptide peptide fused to a second Fc region. In some embodiments, myostatin pathway inhibitor peptide or polypeptide is fused to the C-terminus of the Fc fragment. For example, when the Fc fragment comprises or consists of a CH2 and CH3 region, the myostatin pathway inhibitor peptide or polypeptide may be fused to the C-terminus of the CH3 region.

[0426] In some embodiments a fusion molecule according to the present disclosure comprises: a GLP-1 receptor agonist peptide; an Fc fragment; a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is a peptide or polypeptide; optionally an obesity-related peptide moiety; and optionally a muscle-preserving moiety; wherein the GLP-1 receptor agonist peptide is fused to the Fc fragment via a linker, optionally a protease-cleavable linker, and wherein the myostatin pathway inhibitor peptide or polypeptide is fused to the C-terminus of the Fc fragment. In some embodiments a fusion molecule according to the present disclosure comprises: a first polypeptide comprising, or consisting of, a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is a peptide or polypeptide, fused to fused to the C-terminus of a first Fc fragment; a second polypeptide comprising or consisting of a myostatin pathway inhibitor moiety fused to the C-terminus of a second Fc fragment; a GLP-1 receptor agonist moiety; and optionally a muscle-preserving moiety; optionally wherein (i) the first Fc fragment comprises a knob modification and the second Fc fragment comprises a hole modification, or (ii) the first Fc fragment comprises a hole modification and the second Fc fragment comprises a knob modification.

[0427] In some embodiments a fusion molecule according to the present disclosure comprises: a first polypeptide comprising or consisting of a GLP-1 receptor agonist moiety, wherein the GLP- 1 receptor agonist moiety is a peptide C-terminally fused to the N-terminus of a first Fc fragment, and a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is a peptide or polypeptide fused to the C-terminus of the first Fc fragment; and a second polypeptide comprising or consisting of a GLP-1 receptor agonist moiety C-terminally fused to the N-terminus of a second Fc fragment, and a myostatin pathway inhibitor moiety fused to the C-terminus of the second Fc fragment; optionally wherein (i) the first Fc fragment comprises a knob modification and the second Fc fragment comprises a hole modification, or (ii) the first Fc fragment comprises a hole modification and the second Fc fragment comprises a knob modification.

[0428] In the embodiment described above, the GLP-1 receptor agonist moiety on the first or the second polypeptide may be optionally substituted for any obesity-related peptide moiety disclosed herein. In the embodiment described above, the myostatin pathway inhibitor moiety on the first or the second polypeptide may be optionally substituted for a muscle-preserving moiety.

[0429] In some embodiments, the fusion molecule comprises or consists of a polypeptide complex, comprising (i) a first polypeptide that comprises a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is a peptide or polypeptide, and a first Fc region and (ii) a second polypeptide that comprises a muscle-preserving moiety fused to a second Fc region.

[0430] In some embodiments, a fusion molecule according to the present disclosure comprises a GLP-1 receptor agonist moiety fused to a bimagrumab scFv. In some embodiments, a fusion molecule according to the present disclosure comprises a GLP-1 receptor agonist moiety, an Fc region and a bimagrumab scFv. In some embodiments, a fusion molecule according to the present disclosure comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 64. In some embodiments, a fusion molecule according to the present disclosure comprises a GLP-1 receptor agonist moiety, an Fc region and a bimagrumab scFv. In some embodiments, the GLP-1 receptor agonist moiety is fused to a bimagrumab scFv via a furin-cleavable linker. In some embodiments, a fusion molecule according to the present disclosure comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 65.

[0431] Chemical Conjugates

[0432] A third exemplary fusion molecule according to the present disclosure comprises an obesity-related peptide moiety (e.g. an GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide), wherein the obesity-related peptide moiety is chemically conjugated to a myostatin pathway inhibitor moiety, optionally wherein the myostatin pathway inhibitor moiety is an antibody. The obesity- related peptide moiety may be chemically conjugated to a myostatin pathway inhibitor moiety using any suitable technique as described hereinabove.

[0433] In such fusion molecules, it will be appreciated that the obesity-related peptide moiety is synthesized separately and chemically conjugated to the myostatin pathway inhibitor moiety. Separate synthesis of the obesity-related peptide moiety advantageously allows introduction of chemical modifications (e.g. non-natural amino acids) which can be introduced to improve the pharmacokinetics of the peptide. Accordingly, in some such embodiments, the obesity-related peptide is a GLP-1 agonist peptide having the amino acid sequence set out in SEQ ID NO: 94. Analogously, the myostatin pathway inhibitor moiety can be manufactured using a standard process without yield and purity concerns.

[0434] An exemplary fusion molecule comprising a GLP-1 receptor agonist moiety chemically conjugated to a myostatin pathway inhibitor moiety is shown in Figure 11. In some embodiments, provided herein are fusion molecules according to Figure 11 A. In such embodiments, a myostatin pathway inhibitor moiety as described herein (e.g. an antibody which specifically binds myostatin, activin and / or ACVR2B / 2A as described herein) is chemically conjugated to a GLP-1 receptor agonist moiety (e.g. a lipidated GLP-1 receptor agonist peptide).

[0435] In some embodiments, the myostatin pathway inhibitor moiety is an antibody, and the obesity-related peptide moiety is chemically conjugated to the CH2 region of the antibody. In some embodiments, the myostatin pathway inhibitor moiety is an antibody, and the obesity-related peptide moiety is chemically conjugated to the CH3 region of the antibody. In some embodiments, the myostatin pathway inhibitor moiety is an antibody, and the obesity-related peptide moiety is chemically conjugated to the CL region of the antibody.

[0436] The GLP-1 receptor agonist moiety may comprise modifications to improve in vivo half-life. In some embodiments, the GLP-1 receptor agonist moiety is a peptide that comprises amino acid substitutions relative to native GLP to reduce DPP4 protease cleavage and improve in vivo half-life. In some embodiments, the GLP-1 receptor agonist moiety is a peptide that is lipidated. In some embodiments a fusion molecule according to the present disclosure comprises:

[0437] (i) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an IgG-type antigen binding molecule (e.g. an anti-myostatin antibody);

[0438] (ii) a chemical linker (e.g. a chemical linker comprising a maleimide or bromo-acetamide group); and

[0439] (iii) an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide).

[0440] In some such embodiments a fusion molecule according to the present disclosure comprises:

[0441] (i) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antibody comprising an antibody heavy chain and an antibody light chain (e.g. an anti-myostatin antibody);

[0442] (ii) a chemical linker (e.g. a chemical linker comprising a maleimide or bromo-acetamide group);

[0443] (iii) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide that is chemically conjugated to the myostatin pathway inhibitor moiety; and

[0444] (iv) a muscle-preserving moiety (e.g. an anti-activin A scFv or nanobody), optionally wherein the muscle-preserving moiety is fused to the C-terminus of the antibody heavy chain of the myostatin pathway inhibitor moiety.

[0445] In some embodiments, provided herein are fusion molecules according to Figure 11 B. In some embodiments, the myostatin pathway inhibitor moiety is chemically conjugated to a GLP-1 receptor agonist moiety (e.g. a GLP-1 / GIP or GLP-1 / GCG receptor co-agonist peptide), which is fused to an obesity-related peptide moiety (e.g. a GIP antagonist) via a protease-cleavable linker. The amino acid sequence of the protease-cleavable linker may be modified to adjust cleavage speed. In such embodiments, it is advantageous for the ‘outer’ obesity-related peptide moiety to be associated with lower adverse effects at high concentrations relative to the GLP-1 receptor agonist moiety.

[0446] In some embodiments a fusion molecule according to the present disclosure comprises:

[0447] (i) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an IgG-type antigen binding molecule (e.g. an anti-myostatin antibody);

[0448] (ii) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide, and optionally wherein the GLP-1 receptor agonist moiety is a GLP-1 / GIP or GLP-1 / GCG receptor co-agonist, wherein the GLP-1 receptor agonist moiety is chemically conjugated to the myostatin pathway inhibitor moiety;

[0449] (iii) an obesity-related peptide moiety, optionally wherein the obesity-related peptide moiety is fused to the GLP-1 receptor agonist moiety via a linker (e.g. a furin-cleavable linker); and

[0450] (iv) a muscle-preserving moiety (e.g. an anti-activin A scFv or nanobody).

[0451] In some embodiments, provided herein are fusion molecules according to Figure 11 C. In some embodiments, the myostatin pathway inhibitor moiety is simultaneously conjugated to two warheads ( / .e. a GLP-1 receptor agonist moiety and an obesity-related peptide moiety e.g. GIP antagonist). In some embodiments, a fusion molecule according to the present disclosure comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 89. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 89 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 90.

[0452] In some embodiments, a fusion molecule according to the present disclosure comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 93. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 91 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 93.

[0453] In some embodiments, a fusion molecule according to the present disclosure comprises an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 92. In some embodiments, a fusion molecule according to the present disclosure comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 92 and an amino acid sequence having at least 70% amino acid sequence identity, e.g. one of >75%, >80%, >85%, >90%, >91 %, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to SEQ ID NO: 93.

[0454] Fusion molecules comprising an obesity-related peptide moiety chemically conjugated to a myostatin pathway inhibitor moiety as described herein may also be referred to as ‘conjugates’. Accordingly, provided herein is a conjugate comprising:

[0455] (i) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antibody;

[0456] (ii) a chemical linker comprising a maleimide or bromo-acetamide group; and

[0457] (ii) an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide).

[0458] Also provided is a method of treating obesity, comprising administering a conjugate comprising: (i) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antibody; (ii) a chemical linker comprising a maleimide or bromo-acetamide group; and (ii) an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide). Also provided is a conjugate comprising: (i) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antibody; (ii) a chemical linker comprising a maleimide or bromo-acetamide group; and (ii) an obesity-related peptide moiety (e.g. a GLP-1 receptor agonist moiety, wherein the GLP- 1 receptor agonist moiety is a peptide) for use in a method of treating obesity. Such embodiments may additionally comprise an obesity-related peptide moiety and / or a muscle-preserving moiety as described herein.

[0459] Functional properties

[0460] Fusion molecules described herein may be characterised by reference to certain functional properties. In some embodiments, a fusion molecule described herein may possess one or more of the following properties: binds to the GLP-1 receptor; activates the GLP-1 receptor; binds to myostatin; blocks the action of myostatin; binds to ActRIIA; blocks ActRIIA signalling; binds to ActRIIB; blocks ActRIIB signalling; binds to both ActRIIA and ActRIIB; blocks both ActRIIA and ActRIIB signalling; binds to activin A; promotes weight loss; prevents muscle atrophy; prevents muscle atrophy during weight loss; promotes muscle growth; improve insulin sensitivity; promote blood glucose control; improve lipid profile; induces reduction of fat mass; improves hepatic lipid deposit profile; reduces abdominal fat; improves energy expenditure.

[0461] It will be appreciated that a given fusion molecule may display more than one of the properties recited in the preceding paragraph. A given fusion molecule may be evaluated for the properties recited in the preceding paragraph using suitable assays. For example, the assays may be e.g. in vitro assays, optionally cell-based assays or cell-free assays. In some embodiments, the assays may be e.g. in vivo assays, i.e. performed in non-human animals. In some embodiments, the assays may be e.g. ex vivo assays, i.e. performed using cells / tissue / an organ obtained from a subject. Such assays may be utilised to screen for fusion molecules with a desired functional property. For example, the TGFp / Activin A-Responsive Luciferase Reporter HEK293 Cell Line (also called the SBE HEK293 reporter cell line) is a HEK293 cell line expressing the Firefly luciferase reporter under the control of SMAD-responsive elements (SMAD binding elements, SBE). This cell line can be used to detect inhibition of the myostatin pathway.

[0462] The CHO-K1 / GLP1 R / Ga15 reporter cell line (Genscript) can be used for screening and functional validating agonists of GLP1 R.

[0463] GIP, GCG, GHRH, and amylin receptor reporter cell lines can also be used for screening and functional validating agonists of GIP, GCG, GHRH, and amylin receptor.

[0464] Where assays are cell-based assays, they may comprise treating cells with a given fusion molecule in order to determine whether the fusion molecule displays one or more of the recited properties. Assays may employ species labelled with detectable entities in order to facilitate their detection. Assays may comprise evaluating the recited properties following treatment of cells separately with a range of quantities / concentrations of a given fusion molecule (e.g. a dilution series). When the myostatin pathway inhibitor moiety comprises an antigen-binding molecule, it will be appreciated that the cells preferably express the target antigen for the antigen-binding molecule.

[0465] Analysis of the results of such assays may comprise determining the concentration at which 50% of the maximal level of the relevant activity is attained. The concentration of a given agent at which 50% of the maximal level of the relevant activity is attained may be referred to as the ‘half-maximal effective concentration’ of the agent in relation to the relevant activity, which may also be referred to as the ‘EC50’. By way of illustration, the EC50 of a given fusion molecule for binding to human myostatin may be the concentration of the fusion molecule at which 50% of the maximal level of binding to human myostatin is achieved.

[0466] Depending on the property, the EC50 may also be referred to as the ‘half-maximal inhibitory concentration’ or ‘IC50’, this being the concentration of the agent at which 50% of the maximal level of inhibition of a given property is observed.

[0467] Where the functional properties of agents are compared (e.g. where the fusion molecules of the present disclosure are compared with other polypeptides, such as their constituent polypeptides), comparisons are performed at equivalent concentrations and / or quantity of the relevant agents.

[0468] The ability of a given polypeptide to bind specifically to a given molecule can be determined by analysis according to methods known in the art, such as by ELISA, Surface Plasmon Resonance (SPR; see e.g. Hearty et al., Methods Mol Biol. (2012) 907:41 1-442), Bio-Layer Interferometry (BLI; see e.g. Lad et al., J Biomol Screen (2015) 20(4):498-507), flow cytometry, or by a radiolabeled antigen-binding assay (RIA) enzyme-linked immunosorbent assay. Through such analysis binding to a given molecule can be measured and quantified. In some embodiments, the binding may be the response detected in a given assay.

[0469] Binding affinity of an antigen-binding molecule / moiety for its target is often described in terms of its dissociation constant (KD). Binding affinity can be measured by methods known in the art, such as by ELISA, Surface Plasmon Resonance (SPR; see e.g. Hearty et al., Methods Mol Biol (2012) 907:411-442; or Rich et al., Anal Biochem. (2008) 373(1):112-20), Bio-Layer Interferometry (see e.g. Lad etal., J Biomol Screen (2015) 20(4):498-507; or Concepcion et al., Comb Chem High Throughput Screen. (2009) 12(8)791-800), MicroScale Thermophoresis (MST) analysis (see e.g. Jerabek-Willemsen et al., Assay Drug Dev Technol. (2011) 9(4):342-353), or by a radiolabelled antigen-binding assay (RIA).

[0470] Therapeutic / prophylactic applications

[0471] The fusion molecules, polynucleotides, vectors, cells and compositions described herein find use in therapeutic and prophylactic intervention for disease, e.g. therapeutic and prophylactic intervention for obesity.

[0472] The fusion molecules, polynucleotides, vectors, cells and compositions described herein also find use in methods of controlling body weight, for example controlling weight gain, improving body composition or assisting weight loss.

[0473] In some embodiments is a method of treating or preventing a disease or condition, comprising administering a fusion molecule comprising an obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety as described herein, or a polynucleotide, vector, cell or pharmaceutical composition as described herein, to a patient in need thereof. In some embodiments is a fusion molecule comprising an obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety as described herein, or a polynucleotides, vector, cell or pharmaceutical composition as described herein, for use in a method of treating or preventing a disease or condition. In some embodiments is the use of a fusion molecule comprising an obesity-related peptide moiety fused to a myostatin pathway inhibitor moiety as described herein, or a polynucleotide, vector, cell or pharmaceutical composition as described herein, in the manufacture of a medicament for treating or preventing a disease or condition.

[0474] In any of the embodiments described herein, the disease or condition may be obesity. Obesity is defined as abnormal or excessive fat accumulation that presents a risk to health (World Health Organization). Adults are generally considered obese if they have a body mass index (BMI) of 30 or above. Obesity is associated with co-morbidities such as prediabetes, hypertension, dyslipidemia, fatty liver, weight bearing joint pain, dyspnea or obstructive sleep apnea. The fusion molecules, polynucleotides, vectors, cells and compositions described herein find use in reducing obesity-related morbidity or an obesity-related comorbidity.

[0475] In some embodiments is a method of treating obesity, comprising administering a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to an antigenbinding molecule which is a myostatin pathway inhibitor. In some embodiments is a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to an antigenbinding molecule which is a myostatin pathway inhibitor for use in a method of treating obesity. In some embodiments is the use of a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to an antigen-binding molecule which is a myostatin pathway inhibitor, in the manufacture of a medicament for treating obesity.

[0476] In any of the embodiments described herein, the obesity may be sarcopenic obesity. Sarcopenia is the age-related progressive loss of muscle mass and strength. Sarcopenic obesity is characterised by a combination of high body fat percentage and low skeletal muscle mass. Patients older than 65 years and / or postmenopausal patients are at risk of sarcopenic obesity.

[0477] In any of the embodiments described herein, the disease or condition may be insulin dependent diabetes mellitus or non-insulin dependent diabetes mellitus. Insulin dependent diabetes mellitus is also known as type 1 diabetes. Non-insulin dependent diabetes mellitus is also known as type 2 diabetes. Diabetes occurs when the pancreas does not produce enough insulin (type 1 diabetes) or when the body cannot effectively use the insulin it produces (type 2 diabetes). Hyperglycaemia, also called raised blood glucose or raised blood sugar, is a common effect of uncontrolled diabetes and over time leads to serious damage to many of the body's systems, especially the nerves and blood vessels in the heart, eyes and kidneys.

[0478] In some embodiments is a method of treating insulin dependent diabetes mellitus or non-insulin dependent diabetes mellitus, comprising administering a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antigen binding molecule. In some embodiments is provided a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antigen binding molecule, for use in a method of treating insulin dependent diabetes mellitus or non- insulin dependent diabetes mellitus. In some embodiments is the use of a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor moiety is an antigen binding molecule, in the manufacture of a medicament for treating insulin dependent diabetes mellitus or non-insulin dependent diabetes mellitus.

[0479] Retention of Muscle Mass

[0480] Rapid weight loss (such as GLP-1 receptor agonist-induced weight loss) is often accompanied with significant loss of muscle mass (also called “muscle atrophy”). The therapeutic and prophylactic embodiments described herein may relate to preservation or retention of muscle mass (also called lean muscle mass) during weight loss. In other words, the therapeutic and prophylactic embodiments described herein relate to reduction or prevention of muscle atrophy during weight loss. As used herein, ‘muscle mass’ refers to skeletal muscle mass. Weight loss that is achieved while preventing or reducing muscle atrophy may beneficially result in the subject having an increased basic metabolic rate (BMR), therefore helping prevent or reduce weight gain following termination of treatment. In particular, the fusion molecules of the present disclosure may be used for preventing or reducing muscle atrophy during weight loss. When the fusion molecules of the present disclosure are used in therapeutic and prophylactic applications relating to weight loss, e.g. for the treatment of obesity, the side effect of muscle loss may be reduced or prevented relative to treatment with a GLP-1 receptor agonist peptide alone. In other words, in the therapeutic and prophylactic applications described herein, the weight loss is preferentially fat loss. The term ‘fat loss’ as used herein refers to a reduction of adipose mass in a subject.

[0481] In therapeutic and prophylactic applications of the fusion molecules described herein, more than 60% of the weight loss experienced by a subject is fat loss. For example, more than 60%, more than 65%, more than 70%, more than 75%, more than 80%, more than 90%, more than 95%, or more than 99% of weight loss experienced by a subject is fat loss.

[0482] In therapeutic and prophylactic applications of the fusion molecules described herein, less than 40% of the weight loss experienced by a subject is muscle mass. For example, less than 35%, less than 30%, less than 25%, less than 20%, less than 10%, less than 5%, less than 1 % of weight loss experienced by a subject is muscle mass.

[0483] In therapeutic and prophylactic applications of the fusion molecules described herein, the ratio of fat loss to muscle loss experienced by a subject is at least 2:1 , at least 3:1 , at least 4:1 , at least 5:1 , at least 6:1 , at least 7:1 , at least 8:1 , at least 9:1 or at least 10:1 . Accordingly, the fusion molecules described herein may be used in a method of weight loss where the ratio of fat to muscle loss is at least 2:1 , at least 3:1 , at least 4:1 , at least 5:1 , at least 6:1 , at least 7:1 , at least 8:1 , at least 9:1 or at least 10:1 .

[0484] In particular, the fusion molecules of the present disclosure may be used for preventing or treating sarcopenic obesity. Sarcopenic obesity is characterised by the combination of obesity, defined by high body fat percentage, and sarcopenia, defined as low muscle mass accompanied by low muscle function. Because sarcopenic obesity is a high-risk factor for frailty, comorbidities and mortality, retaining muscle mass is important for patients suffering from sarcopenic obesity.

[0485] In therapeutic and prophylactic applications of the fusion molecules described herein, muscle mass may be retained. Accordingly, in some embodiments is a method of treating or preventing obesity, comprising administering a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety as described herein, or a pharmaceutical composition as described herein, to a patient in need thereof, wherein muscle mass is retained. In some embodiments is a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety as described herein, or a pharmaceutical composition as described herein, for use in a method of treating or preventing obesity, wherein muscle mass is retained. In some embodiments is the use of a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety as described herein, or a pharmaceutical composition as described herein, in the manufacture of a medicament for treating or preventing obesity, wherein muscle mass is retained. In therapeutic and prophylactic applications of the fusion molecules described herein, muscle atrophy may be prevented or reduced. Accordingly, in some embodiments is a method of treating or preventing obesity, comprising administering a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety as described herein, or a pharmaceutical composition as described herein, to a patient in need thereof, wherein muscle atrophy is prevented or reduced. In some embodiments is a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety as described herein, or a pharmaceutical composition as described herein, for use in a method of treating or preventing obesity, wherein muscle atrophy is prevented or reduced. In some embodiments is the use of a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor moiety as described herein, or a pharmaceutical composition as described herein, in the manufacture of a medicament for treating or preventing obesity, wherein muscle atrophy is prevented or reduced.

[0486] In some embodiments is a method of treating obesity while retaining muscle mass, comprising administering a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor.

[0487] In some embodiments is a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor for use in a method of treating obesity while retaining muscle mass. In some embodiments is the use of a fusion molecule comprising an obesity-related peptide moiety (e.g. GLP-1 receptor agonist moiety) fused to a myostatin pathway inhibitor in the manufacture of a medicament for treating obesity while retaining muscle mass.

[0488] Administration

[0489] Administration of the articles of the present disclosure is preferably in a "therapeutically effective” or “prophylactically effective” amount, this being sufficient to show therapeutic or prophylactic benefit to the subject. The actual amount administered, and rate and time-course of administration, will depend on the nature and severity of the disease / condition and the particular fusion molecule administered. Prescription of treatment, e.g. decisions on dosage etc., is within the responsibility of general practitioners and other medical doctors, and typically takes account of the disease / disorder to be treated, the condition of the individual subject, the site of delivery, the method of administration and other factors known to practitioners. Examples of the techniques and protocols mentioned above can be found in Remington’s Pharmaceutical Sciences, 20th Edition, 2000, pub. Lippincott, Williams & Wilkins.

[0490] Administration may be e.g. topical, parenteral, systemic, intracavitary, intraperitoneal, intravenous, intraarterial, intramuscular, intrathecal, subcutaneous, intradermal, oral or transdermal. In some preferred embodiments, administration is intraperitoneal, intravenous, intramuscular, or subcutaneous. Subjects

[0491] The subject in accordance with aspects described herein may be any animal or human. The subject is preferably mammalian, more preferably human. The subject may be a non-human mammal, but is more preferably human. The subject may be male or female. The subject may be a patient. A subject may have been diagnosed with a disease or condition requiring treatment (e.g. obesity, diabetes), may be suspected of having such a disease / condition, or may be at risk of developing / contracting such a disease / condition.

[0492] In some embodiments, the subject to be treated according to a therapeutic or prophylactic method of the present disclosure herein is a subject having, or at risk of developing, obesity (e.g. sarcopenic obesity) or diabetes.

[0493] In embodiments according to the present disclosure, a subject may be selected for treatment according to the methods disclosed herein based on characterisation for certain markers of obesity such as visceral fat, BMI, waist circumference, DEXA imaging.

[0494] For example, subjects may be overweight or obese and have a BMI > 24 (e.g. > 24, > 25, > 26, > 27) with at least one obesity-related comorbidity (e.g. prediabetes, hypertension, dyslipidemia, fatty liver, weight bearing joint pain, dyspnea or obstructive sleep apnea), or BMI > 28 (e.g. > 28, > 29, > 30). Subjects may also have a history of at least one unsuccessful dietary effort to lose body weight.

[0495] In some embodiments, a subject may be selected for treatment according to the methods disclosed herein according to at least one of the following criteria:

[0496] (i) having a BMI > 24 with at least one obesity-related comorbidity (e.g. prediabetes, hypertension, dyslipidemia, fatty liver, weight bearing joint pain, dyspnea or obstructive sleep apnea caused by obesity / overweight), or

[0497] (ii) having a BMI > 28.

[0498] Compositions

[0499] The present disclosure provides a composition comprising a fusion molecule according to the present disclosure.

[0500] The fusion molecules described herein may be formulated as pharmaceutical compositions or medicaments for clinical use and may comprise a pharmaceutically-acceptable carrier, diluent, excipient or adjuvant. Thus, the present disclosure provides a pharmaceutical composition / medicament comprising a fusion molecule described herein.

[0501] The term ‘pharmaceutically-acceptable’ as used herein pertains to compounds, ingredients, materials, compositions, dosage forms, etc., which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of the subject in question (e.g. a human subject) without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio. Each carrier, diluent, excipient, adjuvant, filler, buffer, preservative, anti-oxidant, lubricant, binder, stabiliser, solubiliser, surfactant, masking agent, colouring agent, flavouring agent or sweetening agent of a composition according to the present disclosure must also be ‘acceptable’ in the sense of being compatible with the other ingredients of the formulation. Suitable carriers, diluents, excipients, adjuvants, fillers, buffers, preservatives, anti-oxidants, lubricants, binders, stabilisers, solubilisers, surfactants, masking agents, colouring agents, flavouring agents or sweetening agents can be found in standard pharmaceutical texts, for example, Remington’s ‘The Science and Practice of Pharmacy’ (Ed. A. Adejare), 23rd Edition (2020), Academic Press.

[0502] Compositions may be formulated for topical, parenteral, systemic, intracavitary, intraperitoneal, intravenous, intra-arterial, intramuscular, intrathecal, subcutaneous, intradermal, oral or transdermal routes of administration. In some embodiments, a pharmaceutical composition / medicament may be formulated for administration by injection or infusion, or administration by ingestion. In some embodiments, compositions comprising a fusion molecule according to the present disclosure are formulated for administration by injection.

[0503] Suitable formulations may comprise the relevant article in a sterile or isotonic medium. Medicaments and pharmaceutical compositions may be formulated in fluid, including gel, form. Fluid formulations may be formulated for administration by injection or infusion (e.g. via catheter) to a selected region of the human or animal body.

[0504] Polynucleotides

[0505] Aspects and embodiments of the present disclosure relate to polynucleotides. The polynucleotides or plurality of polynucleotides described herein encode constituent components of fusion molecules and may be useful in methods of producing fusion molecules. Polynucleotides described herein may find further utilisation in therapeutic methods as described herein. That is, the polynucleotide is employed as a gene therapy for inducing expression of the fusion molecule in the subject to which it is administered.

[0506] A 'polynucleotide' refers to a polymer chain of a plurality of nucleotide monomers linked by bonds between the monomers, typically phosphodiester bonds (e.g. in the case of polynucleotides formed by naturally-occurring nucleotide monomers). Polynucleotides include oligonucleotides, which generally comprise <50 nucleotides. A polynucleotide may be single-stranded, or may be double-stranded ( / .e. may comprise a duplex formed by hydrogen-bonding between complementary nucleotides). Polynucleotides according to the present disclosure may comprise or consist of: single-stranded DNA, double-stranded DNA, DNA that is a mixture of single- and double-stranded regions, single-stranded RNA, doublestranded RNA, RNA that is mixture of single- and double-stranded regions, single-stranded molecules comprising DNA and RNA, double-stranded molecules comprising DNA and RNA, and molecules comprising DNA and RNA having a mixture of single- and double-stranded regions.

[0507] Disclosed herein is a polynucleotide encoding any of the fusion molecules disclosed herein comprising a GLP-1 receptor agonist moiety fused to a myostatin pathway inhibitor. In some embodiments, a polynucleotide as disclosed herein encodes a single transcript encoding all domains of a fusion molecule as described herein (e.g. a polynucleotide encoding a single transcript encoding a single multi-domain polypeptide).

[0508] In some embodiments, a fusion molecule according to the present disclosure may be encoded by multiple polynucleotides. For example, when a fusion molecule according to the present disclosure comprises, or consists of, a polypeptide complex, the constituent polypeptides in the polypeptide complex may be encoded by multiple polynucleotides. In some embodiments, constituent polypeptides of a fusion molecule according to the present disclosure are encoded by nucleotide sequences provided in the same reading frame. In some embodiments, the polynucleotide or plurality of polynucleotides encodes a fusion molecule or constituent polypeptides of a fusion molecule.

[0509] Provided herein is a plurality of polynucleotides encoding from 5’ to 3’:

[0510] (i) a first polynucleotide encoding an obesity-related peptide moiety (e.g. GLP-1 receptor agonist), and the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and

[0511] (ii) a second polynucleotide encoding the antibody light chain of the antibody that binds to a myostatin pathway protein.

[0512] Provided herein is a plurality of polynucleotides encoding from 5’ to 3’:

[0513] (i) a first polynucleotide encoding the antibody heavy chain of an antibody that binds to a myostatin pathway protein, and

[0514] (ii) a second polynucleotide encoding an obesity-related peptide moiety (e.g. GLP-1 receptor agonist), and the antibody light chain of the antibody that binds to a myostatin pathway protein.

[0515] Optionally, the polynucleotides disclosed herein may additionally encode further obesity-related peptide moieties and / or muscle-preserving moieties as described herein.

[0516] Provided herein is a plurality of polynucleotides encoding from 5’ to 3’:

[0517] (i) a first polynucleotide encoding a GLP-1 receptor agonist), a first Fc region (e.g. a CH2 and CH3 domain) and a myostatin pathway inhibitor moiety, and

[0518] (ii) a second polynucleotide encoding a GLP-1 receptor agonist), a first Fc region (e.g. a CH2 and CH3 domain) and a myostatin pathway inhibitor moiety.

[0519] In the embodiment described above, the GLP-1 receptor agonist peptide encoded by the first or the second polynucleotide may be optionally substituted for an obesity-related peptide moiety (e.g. selected from obesity-related peptide moiety is a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist). In the embodiment described above, the myostatin pathway inhibitor encoded by the first or the second polynucleotide may be optionally substituted for a musclepreserving moiety. In some embodiments, the polynucleotides described herein comprise a signal peptide for protein secretion. A signal peptide is also known as a leader sequence or signal sequence. Signal peptides normally consist of a sequence of 5-30 hydrophobic amino acids, which form a single alpha helix. Secreted proteins and proteins expressed at the cell surface often comprise signal peptides. Signal peptides are known for many proteins, and are recorded in databases such as GenBank, UniProt and Ensembl, and / or can be identified / predicted e.g. using amino acid sequence analysis tools such as SignalP (Petersen et al., 2011 Nature Methods 8: 785-786) or Signal-BLAST (Frank and Sippl, 2008 Bioinformatics 24: 2172-2176).

[0520] The signal peptide may be present at the N-terminus of the fusion molecule, and may be present in the newly synthesized fusion molecule. The signal peptide provides for efficient trafficking of the fusion molecule. Signal peptides are often removed by cleavage, and thus are not comprised in the mature fusion molecule.

[0521] The polynucleotides of the present disclosure comprise a start codon 5’ to ( / .e. upstream of, in the context of the nucleotide sequence of the polynucleotide) the nucleotide sequence encoding a polypeptide of interest. The start codon is preferably the trinucleotide ‘ATG’.

[0522] In some embodiments, the polynucleotide further comprises a promoter sequence. The promoter sequence is preferably 5’ to the first nucleotide sequence. In some embodiments, the polynucleotide further comprises one or more enhancer sequences. The one or more enhancer sequences are preferably 5’ to the first nucleotide sequence.

[0523] In some embodiments, the polynucleotide further comprises a stop codon. The stop codon is preferably provided immediately 3’ to ( / .e. downstream of, in the context of the nucleotide sequence of the polynucleotide) the trinucleotide encoding the terminal amino acid of the polypeptide encoded by the fifth or sixth nucleotide sequence.

[0524] Vectors

[0525] In some embodiments, the polynucleotides may be, or may be comprised / contained in, a vector, or a plurality of vectors. A ‘vector’ as used herein is a nucleic acid molecule used as a vehicle to transfer exogenous nucleic acid into a cell.

[0526] The vector may facilitate delivery of the polynucleotide(s) encoding a polypeptide according to the present disclosure to a cell. The vector may be an expression vector comprising elements required for expressing a polypeptide according to the present disclosure. The vector may comprise elements facilitating integration of the polynucleotide(s) into the genomic DNA of the cell into which the vector is introduced.

[0527] A vector may facilitate delivery of polynucleotides according to the present disclosure to a cell. A vector may be an expression vector, comprising elements required for producing the fusion molecules according to the present disclosure. Such vectors may include a promoter sequence operably linked to the nucleotide sequence encoding the sequence to be expressed. A vector may also include a termination codon and expression enhancers. Any suitable vectors, promoters, enhancers and termination codons known in the art may be used to express a peptide or polypeptide from a vector according to the present disclosure.

[0528] The term “operably linked” may include the situation where a selected nucleic acid sequence and regulatory nucleic acid sequence (e.g. promoter and / or enhancer) are covalently linked in such a way as to place the expression of nucleic acid sequence under the influence or control of the regulatory sequence (thereby forming an expression cassette). Thus a regulatory sequence is operably linked to the selected nucleic acid sequence if the regulatory sequence is capable of effecting transcription of the nucleic acid sequence. The resulting transcript may then be translated into a desired pe ptid e (s) / po ly pe ptid e (s) .

[0529] Vectors contemplated in connection with the present disclosure include DNA vectors, RNA vectors, plasmids (e.g. conjugative plasmids (e.g. F plasmids), non-conjugative plasmids, R plasmids, col plasmids, episomes), viral vectors (e.g. retroviral vectors, e.g. gammaretroviral vectors (e.g. murine leukemia virus (MLV)-derived vectors, e.g. SFG vector), lentiviral vectors, adenovirus vectors, adeno- associated virus vectors, vaccinia virus vectors and herpesvirus vectors), transposon-based vectors, and artificial chromosomes (e.g. yeast artificial chromosomes), e.g. as described in Maus et al., Annu Rev Immunol. (2014) 32:189-225 and Morgan and Boyerinas, Biomedicines (2016) 4:9, which are both hereby incorporated by reference in their entirety.

[0530] In some embodiments, the vector may be a eukaryotic vector, i.e. a vector comprising the elements necessary for expression of protein from the vector in a eukaryotic cell. In some embodiments, the vector may be a mammalian vector, e.g. comprising a cytomegalovirus (CMV) or SV40 promoter to drive protein expression.

[0531] Cells

[0532] Aspects and embodiments of the present disclosure relate to cells comprising or expressing a fusion molecule according to the present disclosure. Also provided are cells comprising polynucleotides or vectors according to the present disclosure. A cell according to the present disclosure may comprise a vector, or plurality of vectors, comprising the plurality of polynucleotides according to the present disclosure. A cell according to the present disclosure may comprise a polynucleotide encoding a fusion molecule or encoding constituent polypeptides of a fusion molecule. A cell according to the present disclosure may comprise a polynucleotide encoding a fusion molecule, wherein the fusion molecule comprises an obesity-related peptide moiety and a myostatin pathway inhibitor moiety peptide or polypeptide.

[0533] It will be appreciated that where cells are referred to herein in the singular (i.e. ‘a / the cell’), pluralities / populations of such cells are also contemplated.

[0534] The cells disclosed herein may be in vitro and / or may be isolated from the human or animal body. A cell according to the present disclosure may be a eukaryotic cell, e.g. a mammalian cell. The mammal may be a primate (rhesus, cynomolgus, non-human primate or human) or a non-human mammal (e.g. rabbit, guinea pig, rat, mouse or other rodent (including any animal in the order Rodentia), cat, dog, pig, sheep, goat, cattle (including cows, e.g. dairy cows, or any animal in the order Bos), horse (including any animal in the order Equidae), donkey, and non-human primate).

[0535] For recombinant production of fusion molecules according to the present disclosure, any cell suitable for the expression of polypeptides may be used. The cell may be a prokaryote or eukaryote. In some embodiments the cell is a prokaryotic cell, such as a cell of archaea or bacteria. In some embodiments the bacteria may be Gram-negative bacteria such as bacteria of the family Enterobacteriaceae, for example Escherichia coli. In some embodiments, the cell is a eukaryotic cell such as a yeast cell, a plant cell, insect cell or a mammalian cell, e.g. a cell described hereinabove.

[0536] In some embodiments, the cell is, or is derived from, a cell type commonly used for the expression of polypeptides for use in therapy in humans. Exemplary cells are described e.g. in Kunert and Reinhart, Appl Microbiol Biotechnol. (2016) 100:3451-3461 (hereby incorporated by reference in its entirety), and include e.g. CHO, HEK 293, PER.C6, NSO and BHK cells.

[0537] Kits

[0538] The present disclosure also provides kits of parts. A kit according to the present disclosure may comprise components for performing a method described herein, in whole or in part.

[0539] The kit may have at least one container having a predetermined quantity of a fusion molecule or composition described herein.

[0540] In some aspects of the present disclosure a kit of parts is provided. In some embodiments, the kit may comprise a fusion molecule or composition described herein, and which may be provided in a predetermined quantity.

[0541] The kit may provide a fusion molecule or composition described herein together with instructions for administration to a patient in order to treat a specified disease / condition (e.g. a disease / condition described herein, e.g. obesity or diabetes) e.g. in the form of an instruction booklet or leaflet. The instructions may include a protocol for performing any one or more of the methods described herein. The kit may further comprise reagents, buffers and / or standards required for execution of a method according to the present disclosure.

[0542] Sequence identity

[0543] As used herein, ‘sequence identity’ refers to the percent of nucleotides / amino acid residues in a subject sequence that are identical to nucleotides / amino acid residues in a reference sequence, after aligning the sequences and, if necessary, introducing gaps, to achieve the maximum percent sequence identity between the sequences. Pairwise and multiple sequence alignment for the purposes of determining percent sequence identity between two or more amino acid or nucleic acid sequences can be achieved in various ways known to a person of skill in the art, for instance, using publicly available computer software such as ClustalOmega (Sbding, J., Bioinformatics (2005) 21 , 951-960), T-coffee (Notredame etal., J.

[0544] Mol. Biol. (2000) 302, 205-217), Kalign (Lassmann and Sonnhammer, BMC Bioinformatics (2005) 6,298) and MAFFT (Katoh and Standley, Molecular Biology and Evolution (2013) 30(4) 772-780) software. When using such software, the default parameters, e.g. for gap penalty and extension penalty, are preferably used.

[0545] Sequences

[0546] ***

[0547] The present disclosure includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

[0548] The section headings used herein are for organisational purposes only and are not to be construed as limiting the subject matter described.

[0549] Aspects and embodiments of the present disclosure will now be illustrated, by way of example, with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0550] Throughout this specification, including the claims which follow, unless the context requires otherwise, the word ‘comprise,’ and variations such as ‘comprises’ and ‘comprising,’ will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0551] As used herein, a ‘peptide’ refers to a chain of two or more amino acid monomers linked by peptide bonds. A peptide typically has a length in the region of about 2 to 50 amino acids. A ‘polypeptide’ is a polymer chain of two or more peptides. Polypeptides typically have a length greater than about 50 amino acids. Reference herein to peptides, polypeptides and proteins also includes glycopeptides / glycopolypeptides / glycoproteins, lipopeptides / lipopolypeptides / lipoproteins, nucleopeptides / nucleopolypeptides / nucleoproteins, etc.

[0552] As used herein, an amino acid sequence, or a region of a polypeptide, which ‘corresponds’ to a specified reference amino acid sequence or region of a polypeptide has at least 60%, e.g. one of at least >65%, >70%, >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to the amino acid sequence of the amino acid sequence / polypeptide / region. An amino acid sequence / region / position of a polypeptide / amino acid sequence which ‘corresponds’ to a specified reference amino acid sequence / region / position of a polypeptide / amino acid sequence can be identified by sequence alignment of the subject sequence to the reference sequence, e.g. using sequence alignment software such as ClustalOmega (Soding, J. 2005, Bioinformatics 21 , 951-960).

[0553] Similarly, a nucleotide sequence, or a region of a polynucleotide, which ‘corresponds’ to a specified reference nucleotide sequence or region of a polynucleotide has at least 60%, e.g. one of at least >65%, >70%, >75%, >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >97%, >98%, >99% or 100% sequence identity to the amino acid sequence of the nucleotide sequence / polynucleotide / region. A polynucleotide / region / position of a polynucleotide / nucleotide sequence which ‘corresponds’ to a specified reference nucleotide sequence / region / position of a polynucleotide / nucleotide sequence can be identified by sequence alignment of the subject sequence to the reference sequence, e.g. using sequence alignment software such as ClustalOmega (Soding, J. 2005, Bioinformatics 21 , 951-960).

[0554] As used herein, an amino acid sequence (e.g. the amino acid sequence of a peptide / polypeptide / domain / region) which is ‘derived from’ a reference amino acid sequence (e.g. the amino acid sequence of a reference peptide / polypeptide / domain / region) comprises, or consists of, an amino acid sequence having at least 60%, e.g. one of at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the reference amino acid sequence. Similarly, a nucleotide sequence (e.g. a nucleotide sequence of a polynucleotide) which is ‘derived from’ a reference nucleotide sequence comprises, or consists of, a nucleotide sequence having at least 60%, e.g. one of at least 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the reference nucleotide sequence.

[0555] It must be noted that, as used in the specification and the appended claims, the singular forms ‘a,’ ‘an,’ and ‘the’ include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from ‘about’ one particular value, and / or to ‘about’ another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent ‘about,’ it will be understood that the particular value forms another embodiment.

[0556] Where a nucleic acid sequence is disclosed herein, the reverse complement thereof is also expressly contemplated. Methods described herein may preferably be performed in vitro. The term ‘in vitro’ is intended to encompass procedures performed with cells in culture whereas the term ‘in vivo’ is intended to encompass procedures with / on intact multi-cellular organisms.

[0557] Brief Description of the Figures

[0558] Embodiments and experiments illustrating the principles of the present disclosure will now be discussed with reference to the accompanying figures.

[0559] Figure 1. A schematic showing a first exemplary fusion molecule; antibody with peptide fusions. (A) Linkers linking the GLP-1 peptides to the antibody moiety (indicated by arrows). (B) obesity-related peptide moieties. (C) Half-life promoting component. (D) Muscle-preserving molecule e.g. scFv or nanobody (VHH). (E) Antibody (e.g. IgG-type antibody) (F) obesity-related peptide moiety (GLP-1 receptor agonist peptide).

[0560] Figure 2. A schematic showing a second exemplary fusion molecule; a Fc-fragment with peptide and SCFV / VHH fusions. (A) Linkers linking the peptides to the Fc moiety (indicated by arrows). (B) obesity- related peptide moieties (indicated by box). The peptide moiety can be a dual / tri-agonist that simultaneously targets GLP-1 and another indicated obesity-related target. (C) Half-life promoting component (e.g. knob-in-hole modifications). (D) Muscle-preserving molecules e.g. scFv or nanobody (VHH). In this format, two different components to be conjugated into the same molecule and hence provide a possibility for synergy of different modes of action within a fusion entity. (E) GLP-1 receptor agonist peptide.

[0561] Figure 3. (A) Schematic showing structure of fusion molecule. G=GLP-1 receptor agonist, Chain A: N- GLP1-Bimagrumab heavy chain-C; Chain B: N-Bimagrumab light chain-C. (B) AlphaFold structural prediction for fusion molecule (with bimagrumab in scFv format) (grey), superimposed with crystal structure of bimagrumab scFv with ACVR2B receptor (PDB ID 5NHR) (black), RMSD= 0.470. (C) AlphaFold structural prediction for fusion molecule (with bimagrumab in scFv format) (grey), superimposed with crystal structure of GLP-1 peptide hormone bound to Glucagon-Like peptide-1 (GLP- 1) Receptor (PDB ID 6X18) (black), RMSD = 1 .011 . (D) Dose-response curve for GLP-1 R agonism (GLP1 R-CRE-BLA). GLP-1 Receptor agonism (EC50) = 15.46 pM (30.92 pM for GLP-1 moiety). (E) Dose-response curve for myostatin antagonism (HEK-SBE-BLA). Activin receptor antagonism (EC50) = 641.5 pM.

[0562] Figure 4. (A) Schematic showing structure of fusion molecule. G=GLP-1 receptor agonist, Chain A: N- Bimagrumab heavy chain-C; Chain B: N-GLP1 -Bimagrumab light chain-C. (B) AlphaFold structural prediction for fusion molecule (with bimagrumab in scFv format) (grey), superimposed with crystal structure of bimagrumab scFv with ACVR2B receptor (PDB ID 5NHR) (black), RMSD= 0.373. (C) AlphaFold structural prediction for fusion molecule (with bimagrumab in scFv format) (grey), superimposed with crystal structure of GLP-1 peptide hormone bound to Glucagon-Like peptide-1 (GLP- 1) Receptor (PDB ID 6X18) (black), RMSD = 1.163. (D) Dose-response curve for GLP-1 R agonism (GLP1 R-CRE-BLA). GLP-1 Receptor agonism (EC50) = 9.76 pM. (E) Dose-response curve for myostatin antagonism (HEK-SBE-BLA). Activin receptor antagonism (EC50) = 655.2 pM.

[0563] Figure 5. (A) Schematic showing structure of fusion molecule. Chain A: N-GLP-1-Bimagrumab heavy chain-C; Chain B: N-GLP1-Bimagrumab light chain-C. (B) AlphaFold structural prediction for fusion molecule (with bimagrumab in scFv format) (grey), superimposed with crystal structure of bimagrumab scFv with ACVR2B receptor (PDB ID 5NHR) (black), RMSD= 0.372. (C) AlphaFold structural prediction for fusion molecule (with bimagrumab in scFv format) (grey), superimposed with crystal structure of GLP- 1 peptide hormone bound to Glucagon-Like peptide-1 (GLP-1) Receptor (PDB ID 6X18) (black), RMSD = 0.889. (D) Dose-response curve for GLP-1 R agonism (GLP1 R-CRE-BLA). GLP-1 Receptor agonism (EC50) = 9.827 pM. (E) Dose-response curve for myostatin antagonism (HEK-SBE-BLA). Activin receptor antagonism (EC50) = 690.2 pM.

[0564] Figure 6. (A) Schematic showing structure of fusion molecule. G=GLP-1 receptor agonist, B=Bimagrumab scFv. Chain A: N-Bimagrumab heavy chain-BimaScfv-C; Chain B: N-GLP1-Bimagrumab light chain-C. (B) Dose-response curve for GLP-1 R agonism (GLP1 R-CRE-BLA). GLP-1 Receptor agonism (EC50) = 8.177 pM. (C) Dose-response curve for myostatin antagonism (HEK-SBE-BLA). Activin receptor antagonism (EC50) = 56.64 pM.

[0565] Figure 7. (A) Schematic showing structure of fusion molecule (GB002 / OB060). G=GLP-1 receptor agonist, B=Bimagrumab scFv. Chain A: N-GLP-1-Bimagrumab heavy chain-BimaScfv-C; Chain B: N- Bimagrumab light chain-C. (B, D) Dose-response curve for GLP-1 R agonism (GLP1 R-CRE-BLA). GLP-1 Receptor agonism (EC50) = 5.418 pM (B) and 5.696 (D). (C, E) Dose-response curve for myostatin antagonism (HEK-SBE-BLA). Activin receptor antagonism (EC50) = 37.48 pM (C) and 36.79 (E).

[0566] Figure 8. (A) Schematic showing structure of fusion molecule (OB028). G=GLP-1 receptor agonist, B=Bimagrumab scFv. Chain A: N-GLP1-Fc-BimaScfv-C. (B, D). Dose-response curve for GLP-1 R agonism (GLP1 R-CRE-BLA). GLP-1 Receptor agonism (EC50) = 11684 pM (B) and 4.912 pM (C). (C, E). Dose-response curve for myostatin antagonism (HEK-SBE-BLA). Activin receptor antagonism (EC50) = 209.4 pM (C) and 281 .3 pM (E).

[0567] Figure 9. (A) Schematic showing structure of fusion molecule (OB055). G=GLP-1 receptor agonist, B=Bimagrumab scFv. Chain A: N-GLP1-RVRR-Fc-BimaScfv-C. (B, D) Dose-response curve for GLP-1 R agonism (GLP1 R-CRE-BLA). GLP-1 Receptor agonism (EC50) = 3917 pM (B) and 629 pM (D). (C, E) Dose-response curve for myostatin antagonism (HEK-SBE-BLA). Activin receptor antagonism (EC50) = 144.2 pM (C) and 899.3 pM (E).

[0568] Figure 10. A schematic showing a further exemplary fusion molecule; antibody with peptide fusions. Peptide 1 is an obesity-related peptide moiety (e.q. a GIP antagonist); Peptide 2 is a GLP-1 receptor agonist peptide (e.q. a GLP-1 / GLP-1 and glucagon (GCG) receptor co-agonist). Figure 11. A schematic showing a further exemplary fusion molecule; antibody with chemically conjugated GLP-1 receptor agonist peptide. (A) Antibody (e.g. anti-myostatin or anti-ACVRIIA / B) conjugated to a GLP-1 receptor agonist peptide which is optionally lipidated. Conjugation chemistry may be e.g. maleimide or bromo-acetamide. (B) Antibody conjugated to a GLP-1 receptor agonist peptide (e.g. a GLP-1 / GIP or GLP-1 / GCG receptor co-agonist peptide), which is fused to an obesity-related peptide moiety e.g. GIP antagonist) via a furin-cleavable linker. The linker sequence may be modified to adjust cleavage speed. (C) Antibody simultaneously conjugated to two warheads ( / .e. a GLP-1 receptor agonist and an obesity-related peptide moiety e.g. GIP antagonist).

[0569] Figure 12. (A) Schematic showing the structure of Fusion-001 and Fusion-002. (B) Fat mass changes relative to day 0 (DO) for Fusion-001 and Fusion-001 compared to PBS (vehicle), weight loss reference (WL) Dulaglutide and muscle preservation reference (MP-1) Bimagrumab, (C) Lean mass changes relative to day 0 (DO) for Fusion-001 and Fusion-001 compared to vehicle, WL and MP-1 . (D) Relative percentages of fat mass and lean mass at day 14 (D14) compared to DO. Fusion-001 , Fusion-002, Fusion-001 (2x; double dose), vehicle, MP-1 , WL and MP-1+WL combination were administered on DO. At D14, administration of the Fusion-002 design resulted in a higher relative percentage increase in lean body mass than double the dose of Fusion-001 design. F = Fat Mass, L = Lean Mass.

[0570] Figure 13. (A) Diagrams showing Alphafold prediction of atomic distance between the heavy chain CDR3 of an anti ACVR2B scFv and the GLP-1 peptides using a GGGGS linker, peptide protection linker, HCG- CTP peptide, HCG-CTP-CL peptide, IGG2-H linker, IGG4-H linker, PRO-Rich linker and SER-Rich linker. Superimpositions of all 5 models predicted from Alphafold are shown for each linker. (B) Schematic showing relative distance between GLP-1 Peptide to the H-CDR3 of the anti ACVR2B scFv for the selected linkers.

[0571] Figure 14. Schematics showing exemplary fusion molecules (antibody with peptide fusions). Anti-activin receptor (Bimagrumab (Bima)) scFv is fused to the C-terminus of anti-myostatin antibody (Landogrozumab (Lando)) heavy chain. Obesity related peptide is fused to the N-terminus of the anti- myostatin antibody heavy chain (A-F, I and J) or to the C-terminus of the anti-myostatin antibody light chain (G). Obesity related peptide is Glucagon-like peptide 1 (GLP-1) receptor agonist (A), gastric inhibitory peptide (GIP) receptor agonist (B, C), Glucagon (GCG) receptor agonist (D), Growth Hormone Releasing Hormone (GHRH) receptor agonist (E, F), Amylin (G), or Neprilysin (NEP)-resistant GLP-1 (I, J)

[0572] Figure 15. Schematics showing exemplary fusion molecules (antibody with GLP-1 fusions). (A) OB322 / OB223; GLP-1 fused to the N-terminus of the heavy chain of an anti-activin receptor 2B antibody (ANB-012). (B) OB323 / OB223; GLP-1 fused to the N-terminus of the heavy chain of an anti-activin receptor 2B antibody (ANB-012) and an ANB-012 scFv was fused to the C-terminus of the heavy chain. (C) OB324 / OB041 ; GLP-1 fused to the N-terminus of the heavy chain of an anti-myostatin antibody (Landogrozumab (-K); Landogrozumab antibody without the final Lysine) and an ANB-012 scFv was fused to the C-terminus of the heavy chain. Figure 16. Bimagrumab E380C Mutant retains biological activity. Dose-response curves for Bimagrumab (left panel) and Bimagrumab E380C mutant (right panel) using HEK-SBE-BLA reporter cell-based assay after (A) myostatin stimulation and (B) activin A stimulation

[0573] Figure 17. Murinized Bimagrumab and murinized Bimagrumab Q382C mutants retain biological activity. Dose-response curve after myostatin stimulation using HEK-SBE-BLA reporter cell-based assay.

[0574] Figure 18. Schematic showing the workflow for production and purification of antibody-peptide conjugates (APCs).

[0575] Figure 19. Liquid Chromatography-Mass Spectrometry (LC-MS) confirming generation of mAb- mB_Q382C conjugate with Glucagon-Like peptide-1 (GLP-1) Peptide. High-performance liquid chromatography-time-of-flight mass spectrometry (HPLC-TOF-MS) was performed using Agilent PLRP-S 4000 A, 5.0 pM, 2.1 x 50 mm column. Expected value for light chain (LC) = 23471 Da, found value for LC = 23417.00 Da (denatured), expected value for heavy chain (HC) = 48987, found value for HC = 48087.0 (denatured), expected value for heavy chain plus GLP-1 peptide (HC+1* peptide) = 52608, found value for HC+1* peptide = 52608.5 Da (denatured).

[0576] Figure 20. Biological activity of antibody-peptide fusions. (A). Dose-response curve for Glucagon-Like peptide-1 receptor (GLP-1 R) agonism (GLP1 R-CRE-bla CHO-K1 cell-based assay). GLP-1 Receptor agonism (EC50) = 3917 pM. (B). Dose-response curve for myostatin antagonism (HEK-SBE-BLA).

[0577] Figure 21. Schematics showing exemplary fusion molecules (antibody with peptide fusions). (A) OB367 / OB368 / OB041 ; anti-activin receptor 2B (ANB-012) scFv is fused to the C-terminus of an anti- myostatin antibody (Landogrozumab (Lando)) heavy chain. The Fc region of the anti-myostatin antibody (human lgG4; hlGG4) comprises ‘knob-into-hole’ (KIH) modifications. (B) OB369 / OB370 / OB041 ; anti- activin receptor 2B (ANB-012) scFv is fused to the C-terminus of an anti-myostatin antibody (Lando) heavy chain. The anti-myostatin antibody Fc region comprises KIH modifications that facilitate pairing of asymmetric heavy chain pairs. Glucagon-Like peptide-1 (GLP-1) is fused to the N-terminus of the first heavy chain (comprising a ‘knob’ mutation) and gastric inhibitory peptide (GIP) is fused to the N-terminus of the second heavy chain (comprising a ‘hole’ mutation). (C) OB369 / OB371 / OB041 ; anti-activin receptor 2B (ANB-012) scFv is fused to the C-terminus of an anti-myostatin antibody (Lando) heavy chain. The anti-myostatin antibody Fc region comprises KIH modifications that facilitate pairing of asymmetric heavy chain pairs. Glucagon-Like peptide-1 (GLP-1) is fused to the N-terminus of the first heavy chain (comprising a ‘knob’ mutation) and Growth Hormone Releasing Hormone (GHRH) is fused to the N- terminus of the second heavy chain (comprising a ‘hole’ mutation).

[0578] Figure 22. Biological activity of antibody-peptide fusions. Dose-response curve for myostatin agonism (HEK-SBE-BLA reporter cell-based assay) for fusion molecules a Bimagrumab scFv fused to the C- terminus of the heavy chain of Landogrozumab (OB325 / OB041) and fusion molecules comprising a Bimagrumab scFv fused to the C-terminus of the heavy chain of Landogrozumab and an obesity-related peptide moiety fused to the N-terminus of the heavy chain of Landogrozumab: GLP-1 (OB326 / OB041), GLP-I-NEP(R) (OB365 / OB041 and OB366 / OB041), GIP (1-42) (OB359 / OB041), GIP (1-30) (GB360 / GB041), GCG (OB361 / OB041), GHRH (OB362 / OB041) and GHRH (1-30) (OB363 / OB041), fusion molecules comprising a Bimagrumab scFv fused to the C-terminus of the heavy chain of Landogrozumab and Amylin fused to the C-terminus of the light chain of Landogrozumab (OB364 / OB041) and compared to Landogrozumab and Bimagrumab.

[0579] Figure 23. Biological activity of antibody-peptide fusions. (A). Dose-response curve for Glucagon-Like peptide-1 receptor (GLP-1 R) agonism (GLP1 R-CRE-bla CHO-K1 cell-based assay). Fusion molecules have a Bimagrumab scFv fused to the C-terminus of the heavy chain of Landogrozumab and GLP-1 or NEP resistant GLP-1 (GLP-1 (OB204) and GLP-1 (OB206)) fused to the N-terminus of the heavy chain of Landogrozumab. (B, C). Dose-response curve for Glucagon-Like peptide-1 receptor (GLP-1 R) agonism (GLP1 R-CRE-bla CHO-K1 cell-based assay) with and without neutral endopeptidase (NEP) treatment. “-NEP” indicates NEP treated sample.

[0580] Figure 24. Biological activity of antibody-peptide fusions. (A). Dose-response curve for gastric inhibitory peptide receptor (GIP-R) agonism (GIPR-CRE-bla HEK 293T cell-based assay) for fusion molecules comprising a Bimagrumab scFv fused to the C-terminus of the heavy chain of Landogrozumab and GIP (1-42) (OB359 / OB041) or GIP (1-30) (OB360 / OB041) fused to the N-terminus of the heavy chain of Landogrozumab. (B). Dose-response curve for glucagon receptor (GCG-R) agonism (GCGR-CRE-bla CHO-K1 cell-based assay) for fusion molecules comprising a Bimagrumab scFv fused to the C-terminus of the heavy chain of Landogrozumab and GCG (OB361 / OB041) fused to the N-terminus of the heavy chain of Landogrozumab. (C). Dose-response curve for Growth Hormone Releasing Hormone receptor (GHRH-R) agonism (CHO-K1 GHRHR Gs cell-based assay) for fusion molecules comprising a Bimagrumab scFv fused to the C-terminus of the heavy chain of Landogrozumab and GHRH (OB362 / OB041) and GHRH (1-30) (OB363 / OB041) fused to the N-terminus of the heavy chain of Landogrozumab.

[0581] Examples

[0582] Example 1 : Materials and Methods

[0583] 1.1 Simulations

[0584] Bifunctional molecular models were designed and feasibility analysis was performed using AlphaFold (Jumper et al. Nature, (2021) 596, pages 583-589).

[0585] As the modification / fusion site only involves the N-terminal variable chains of the antibody, the single chain variable fragment (scFv) was used for simulation instead of the full mab to reduce the demand for computational power and to increase the accuracy (resolution) of the prediction from AlphaFold. The simulation was conducted as a monomer form (to assess structure and folding integrity of both the fusion partner) and multimeric form to validate the binding ability of individual components to their cognate antigens. Root mean square deviation (RMSD) was determined between predicted structure of fusion molecules and superimposition of individual components.

[0586] 1.2 Cell Transfection and Protein Expression

[0587] Fusion proteins were expressed and purified using affinity chromatography and FPLC purification.

[0588] Preparation of Work Area and Reagents

[0589] The biological safety cabinet (BSC) was disinfected with 75% ethanol, and essential equipment was placed inside. UV sterilization was performed for at least 30 minutes. ExpiCHO™ Expression Medium was pre-warmed at 37°C, while ExpiFectamine™ CHO Reagent and OptiPRO™ SFM Complexation Medium were kept at 4°C. On the transfection day, only cells with a density of 7 x 10A6 to 10 x 10A6 viable cells / mL and 95-99% viability were used.

[0590] Cell Transfection

[0591] Cells were diluted to 6 x 1OA6 viable cells / mL in fresh, pre-warmed ExpiCHO™ Expression Medium. High-density cells were discarded. ExpiFectamine™ CHO / plasmid DNA complexes were prepared using cold reagents. Plasmid DNA (0.5-1 .0 pg per mL of culture) was diluted in OptiPRO™ SFM Medium, mixed gently, and combined with ExpiFectamine™ CHO Reagent. The mixture was incubated at room temperature for 1-5 minutes before being added to the cell culture while swirling gently. Cultures were incubated at 37°C with 8% CO2 on an orbital shaker.

[0592] Post-Transfection Enhancements

[0593] At 18-22 hours post-transfection, different protocols were applied:

[0594] • Standard Protocol: ExpiFectamine™ CHO Enhancer and ExpiCHO™ Feed were added, and incubation continued at 37°C with 8% CO2.

[0595] • High Titer Protocol: Enhancer and Feed were added, followed by transfer to 32°C with 5% CO2.

[0596] • Max Titer Protocol: Similar to High Titer, with additional ExpiCHO™ Feed on Day 5.

[0597] Protein Harvest

[0598] The optimal harvest time varied by protocol:

[0599] • Standard Protocol: 8-10 days post-transfection.

[0600] • High Titer Protocol: 10-12 days post-transfection.

[0601] • Max Titer Protocol: 12-14 days post-transfection.

[0602] Shaking speeds and reagent volumes were adjusted based on culture scale, ensuring proper mixing and optimal protein expression.

[0603] Protein G Column Purification

[0604] The Protein G column was equilibrated with 5-10 column volumes (CV) of 20 mM sodium phosphate (pH 7.0). The protein-containing supernatant was clarified by centrifugation and filtered before loading onto the column. The sample was applied at 1-2 mL / min, followed by washing with 5-10 CV of binding buffer. Bound antibodies were eluted with 2-5 CV of 0.1 M glycine-HCI (pH 2.7) and immediately neutralized with 1 M Tris-HCI (pH 9.0).

[0605] Eluted fractions were pooled and subjected to buffer exchange or concentration as needed. The column was regenerated with 5 CV of 20% ethanol and stored at 2-8°C. Reuse was restricted to identical monoclonal antibodies to prevent cross-contamination.

[0606] 1.3 ELISA

[0607] Maxisorp 96-well ELISA plates (Thermo Fisher Scientific) were coated overnight at 2-8°C with 1-10 pg / mL recombinant protein antigen in 50 mM bicarbonate buffer (pH 9.4-9.6). After washing with PBST and PBS, plates were blocked with 1% or 2% BSA in PBS for 2 hours at 37°C or overnight at 4°C. Test samples, serially diluted 3-fold in blocking buffer starting at 15 pg / mL, were added (100 pL / well) and incubated for 1 .5 hours at 37°C or overnight at 4°C. Following three PBST washes, secondary antibodies (goat anti-human IgG Fc-HRP or goat anti-mouse IgG Fc-HRP, [Supplier Name]) diluted 1 :10000 or 1 :50000 in blocking buffer were added (100 pL / well) and incubated for 1 hour at 37°C. After washing with PBST, 100 pL SureBlue™ TMB Peroxidase Substrate (SeraCare) was added and incubated at 37°C for 10 minutes in the dark. The reaction was stopped with 100 pL stop solution (SeraCare), and the OD450 was measured using a PerkinElmer microplate reader (Victor Nivo model) (Thermo Fisher Scientific).

[0608] 1.4 SBE-bla HEK293 reporter cell line assay and GLP1R-CRE-bla CHO-K1 cell lines assay Biological activity of the fusion molecules as a myostatin pathway inhibitor was confirmed using the activin A / myostatin-Activin 2A / 2B receptor axis functional validation platform (SBE-bla HEK293 reporter cell line).

[0609] The CellSensor™ SBE-bla HEK 293T (HEK-SBE-BLA) and GeneBLAzer® GLP1 R-CRE-bla CHO-K1 (GLP1 R-CRE-BLA) cell lines were used to evaluate SMAD2 / 3 pathway antagonism (myostatin or activin A inhibition) and GLP-1 R agonism, respectively, following the manufacturer’s protocol. Briefly, 40,000 cells were seeded per well in assay medium containing 1 .0% FBS in a black, transparent-bottom 96-well plate (total volume: 64 pL) and incubated overnight in a humidified CO2incubator at 37°C. For myostatin / activin A antagonism assays using CellSensor™ SBE-bla HEK 293T cells, cells were pretreated with varying concentrations of the antagonist for 30 minutes, followed by the addition of a fixed concentration of agonist ligands (8 pL of 10 ng / mL myostatin or 5 ng / mL activin A), and further incubated for 5 hours. After incubation, 8 pL of fluorogenic substrate (LiveBLAzer™-FRET B / G Loading Kit) was added to each well, followed by a 2-hour incubation at room temperature. Fluorescence was measured using a multi-plate reader at two excitation / emission channels (409 / 460 nm and 409 / 530 nm). For GLP- 1 R agonism assays using GeneBLAzer® GLP1 R-CRE-bla CHO-K1 cells, the procedure was identical except that the antagonist addition was replaced with 8 pL of assay medium, and no pre-incubation was required. 1.5 GLP-1 R agonist reporter assay

[0610] The GLP-1 receptor agonism activity of the aliquoted samples was determined using GeneBLAzer™ GLP1 R-CRE-bla CHO-K1 reporter Cell line (ThermoFisher scientific Catalog number K1783) as per the manufacturer protocol.

[0611] 1.6 GIP-R agonist reporter assay

[0612] The GIP receptor agonism activity of the samples was determined using GeneBLAzer™ GIPR-CRE-bla HEK 293T Cells (ThermoFisher scientific Catalog number K1864) as per the manufacturer protocol.

[0613] 1.7 GCG-R agonist reporter assay

[0614] The GCG receptor agonism activity of the samples was determined using GeneBLAzer™ GCGR-CRE- bla CHO-K1 Cells (ThermoFisher scientific Catalog number K1855) as per the manufacturer protocol.

[0615] 1.8 Human GHRH agonist reporter assay

[0616] To evaluate the efficacy of the hGHRH-Bi-specifics fusions, the cAMP Hunter™ CHO-K1 GHRHR Gs Cell Line kit (Eurofins DiscoverX Catalog Number: 95-0076C2) was utilized. The experiments were conducted following the manufacturer's recommended protocol. Specifically, the cells were cultured and treated according to the guidelines provided in the kit's manual to ensure optimal conditions for assessing cAMP response. This approach allowed accurate measurement of the analogue's activity and stability in a controlled environment.

[0617] 1.9 NEP Degradation Assay

[0618] The assay buffer comprised 25 mM HEPES, 150 mM NaCI, 0.01% Tween-20, 0.1% bovine serum albumin (BSA), and 1% penicillin-streptomycin (PS). Where indicated, 5 pM zinc chloride (ZnCI2; Sigma- Aldrich) was added to support metalloprotease activity. All reagents were sterile-filtered prior to use. The buffer was prepared fresh and equilibrated to room temperature immediately before use.

[0619] Recombinant neutral endopeptidase (NEP; BioLegend, Cat. No. 790504) was diluted to 1 pg / mL in assay buffer. Substrate protein was diluted from stock to a final assay concentration of 0.5-1 pM, depending on experimental requirements. Reaction mixtures (50 pL total volume) contained assay buffer, NEP enzyme, and substrate protein. Components were gently mixed by pipetting and incubated at 37 °C for 24 h. Aliquots (5 pL) were collected at designated time points and immediately flash-frozen in liquid nitrogen.

[0620] Example 2: Generation and characterisation of exemplary Fusion Molecules

[0621] 2.1 GLP-1 peptide fused to N-terminal of the Heavy chain of Bimagrumab

[0622] The structure of the fusion molecule is shown in Figure 3A. The sequence of Chain A is set out in SEQ ID NO: 60. The sequence of Chain B is set out in SEQ ID NO: 53.

[0623] Feasibility analysis was performed using AlphaFold (Figures 3B and 3C). The predicted structure of the fusion molecule was superimposed with crystal structure 5NHR (Bimagrumab scFv with ACVR2B receptor), RMSD = 0.363 (Figure 3B) and crystal structure 6X18 (GLP-1 peptide hormone bound to Glucagon-Like peptide-1 (GLP-1) Receptor), RMSD = 1.011 (Figure 3C). The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 23.33 mg / L. The purity before FPLC purification was 95.7 %.

[0624] GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 3D and Figure 3E). GLP-1 Receptor agonism (EC50) was 15.46 pM (30.92 pM for GLP-1 moiety) and Activin receptor antagonism (EC50) was 641 .5 pM.

[0625] 2.2 GLP-1 peptide fused to N-terminal of the light chain of Bimagrumab

[0626] The structure of the fusion molecule is shown in Figure 4A. The sequence of Chain A is set out in SEQ ID NO: 52. The sequence of Chain B is set out in SEQ ID NO: 61 .

[0627] Feasibility analysis was performed using AlphaFold (Figures 4B and 4C). The predicted structure of the fusion molecule was superimposed with crystal structure 5NHR (Bimagrumab scFv with ACVR2B receptor), RMSD = 0.373 (Figure 4B) and crystal structure 6X18 (GLP-1 peptide hormone bound to Glucagon-Like peptide-1 (GLP-1) Receptor), RMSD = 1.163 (Figure 4C).

[0628] The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 23.33 mg / L. The purity before FPLC purification was 83.59 %.

[0629] GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 4D and Figure 4E). GLP-1 Receptor agonism (EC50) was 9.76 pM and Activin receptor antagonism (EC50) was 655.2 pM.

[0630] 2.3 GLP-1 peptide fused to N-terminal of the Heavy chain and light chain of Bimagrumab

[0631] The structure of the fusion molecule is shown in Figure 5A. The sequence of Chain A is set out in SEQ ID NO: 60. The sequence of Chain B is set out in SEQ ID NO: 61 .

[0632] Feasibility analysis was performed using AlphaFold (Figures 5B and 5C). The predicted structure of the fusion molecule was superimposed with crystal structure 5NHR (Bimagrumab scFv with ACVR2B receptor), RMSD = 0.372 (Figure 5B) and crystal structure 6X18 (GLP-1 peptide hormone bound to Glucagon-Like peptide-1 (GLP-1) Receptor), RMSD = 0.889 (Figure 5C).

[0633] The fusion molecule was successfully expressed and purified. Extremely low yield of recombinant protein was obtained when GLP-1 s were attached to the N-terminus of both the heavy and light chains of the antibody. The yield after affinity chromatography and FPLC purification was 2.133 mg / L. The purity before FPLC purification was 83.76 %. GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 5D and Figure 5E). GLP-1 Receptor agonism (EC50) was 9.827 pM and Activin receptor antagonism (EC50) was 690.2 pM.

[0634] 2.4 GLP-1 peptide fused to N-terminal of the Light chain of Bimagrumab + Bimacirumab scFv fused to C- terminus of the heavy chain of Bimagrumab

[0635] In this example, an additional activin receptor 2A / 2B binding domain was added to the C-terminus of Bimagrumab heavy chain to investigate whether it is possible to compensate for any potential loss of binding potency due to the linkage of GLP-1 to N-terminus of the heavy chain. The structure of the fusion molecule is shown in Figure 6A (GB005 / OB059). The sequence of Chain A is set out in SEQ ID NO: 62. The sequence of Chain B is set out in SEQ ID NO: 61 .

[0636] The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 0.81 mg / L. The purity before FPLC purification was 85.2 %. In the second batch, the yield was increased to 12.62 mg / L and the purity before FPLC purification was 88.44 %.

[0637] GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 6B and Figure 6C). GLP-1 Receptor agonism (EC50) was 8.177 pM and Activin receptor antagonism (EC50) was 56.64 pM.

[0638] 2.5 GLP-1 peptide fused to N-terminal of the heavy chain of Bimagrumab with Bimagrumab scFv fused to C-terminus + Light chain of Bimagrumab

[0639] In this example, an additional activin receptor 2A / 2B binding domain were added to the C-terminus of Bimagrumab heavy chain to investigate whether it is possible to compensate for any potential loss of binding potency due to the linkage of GLP-1 to N-terminus of the light chain. The structure of the fusion molecule is shown in Figure 7A (QB002 / QB060). The sequence of Chain A is set out in SEQ ID NO: 63. The sequence of Chain B is set out in SEQ ID NO: 53.

[0640] The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 1.09 mg / L. The purity before FPLC purification was 81.83 %. GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 7B and Figure 7C). GLP-1 Receptor agonism (EC50) as determined using the SBE-bla HEK293 reporter cell line assay was 5.418 pM and Activin receptor antagonism (EC50) was 37.48 pM.

[0641] In the second batch, the yield increased to 22.83 mg / L and the purity before FPLC purification was 91 .42 %. GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 7D and Figure 7E). GLP-1 Receptor agonism (EC50) as determined using the SBE-bla HEK293 reporter cell line assay was 5.696 pM and Activin receptor antagonism (EC50) was 36.79 pM. 2.6 GLP-1 peptide fused to N-terminal of the Fc + Bimagrumab scFv fused to C-terminus of the Fc A bimagrumab scFv (form of mini binder) was attached to the C-terminus of the Fc while GLP-1 was fused to the N-terminus of the Fc. This design aimed to reduce inter-domain interactions that could lead to reduced potency of both domains. The structure of the fusion molecule is shown in Figure 8A (OB028). The sequence is set out in SEQ ID NO: 64.

[0642] The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 3.38 mg / L. The purity before FPLC purification was 77.37 %. GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 8B and Figure 8C). GLP-1 Receptor agonism (EC50) as determined using the SBE-bla HEK293 reporter cell line assay was 11684 pM and myostatin antagonism (EC50) was 209.4 pM.

[0643] In the second batch, the yield increased to 76.15 mg / L and the purity before FPLC purification was 66.64 %. GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 8D and Figure 8E). GLP-1 Receptor agonism (EC50) as determined using the SBE-bla HEK293 reporter cell line assay was 4.612 pM and myostatin antagonism (EC50) was 281.3 pM.

[0644] 2.7 GLP-1 peptide fused to N-terminal of the Fc + Bimagrumab scFv fused to C-terminus of the Fc This design aimed to reduce inter-domain interactions that could lead to reduced potency of both domains. An additional RVRR furin-cleavable linker was included for potential release of the peptide from the fusion. The structure of the fusion molecule is shown in Figure 9A (OB055). The sequence is set out in SEQ ID NO: 65.

[0645] The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 1.02 mg / L. The purity before FPLC purification was 78.7 %. GLP-1 and myostatinbinding regions of the fusion proteins were shown to retain binding affinity (Figure 9B and Figure 9C). GLP-1 Receptor agonism (EC50) as determined using the SBE-bla HEK293 reporter cell line assay was 3917 pM and Activin receptor antagonism (EC50) was 144.2 pM.

[0646] In the second batch, the yield increased to 59.13 mg / L and the purity before FPLC purification was 63.06 %. GLP-1 and myostatin-binding regions of the fusion proteins were shown to retain binding affinity (Figure 9D and Figure 9E). GLP-1 Receptor agonism (EC50) as determined using the SBE-bla HEK293 reporter cell line assay was 629 pM and myostatin antagonism (EC50) was 899.3 pM.

[0647] This design shows that incorporating a further muscle-retaining molecule (e.g. a Bimagrumab scFv on the C-terminal of the Fc) can overcome a potential loss of potency of the myostatin pathway inhibitor. These fusion molecules are therefore an improvement over existing molecules (e.g. GLP-1 receptor and glucagon receptor dual agonists). 2.8 Obesity-related peptides fused to the N-terminus of the heavy chain of a myostatin pathway inhibitor antibody with muscle preserving moiety scFv fused to the C-terminus of the heavy chain of the myostatin pathway inhibitor antibody

[0648] Various obesity-related peptides were fused to the N-terminus of the heavy chain of an anti-myostatin antibody (Landogrozumab), and an Anti-activin receptor (Bimagrumab) scFv (form of mini binder) was fused to the C-terminus of the heavy chain of Landogrozumab. 20GS linkers were used between the obesity-related peptides and the antibody. The fusion molecules were expressed and purified. In vitro bioactivity of the fusion molecules was tested.

[0649] GLP-1 was fused to the N-terminus of the heavy chain of Landogrozumab and a Bimagrumab scFv was fused to the C-terminus of the heavy chain of Landogrozumab. The structure of the fusion molecule is shown in Figure 14A (OB326 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 78. The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 118.7 mg / L. The purity before FPLC purification was 90.07 %.

[0650] GIP (1-42) was fused to the N-terminus of the heavy chain of Landogrozumab and a Bimagrumab scFv was fused to the C-terminus of the heavy chain of Landogrozumab. The structure of the fusion molecule is shown in Figure 14B (OB359 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 79. The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 187.0 mg / L. The purity before FPLC purification was 95.12 %.

[0651] GIP (1-30) was fused to the N-terminus of the heavy chain of Landogrozumab and a Bimagrumab scFv was fused to the C-terminus of the heavy chain of Landogrozumab. The structure of the fusion molecule is shown in Figure 14C (OB360 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 80. The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 178.3 mg / L. The purity before FPLC purification was 93.62 %.

[0652] GCG was fused to the N-terminus of the heavy chain of Landogrozumab and a Bimagrumab scFv was fused to the C-terminus of the heavy chain of Landogrozumab. The structure of the fusion molecule is shown in Figure 14D (OB361 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 81 . The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 233.3 mg / L. The purity before FPLC purification was 96.7 %.

[0653] GHRH was fused to the N-terminus of the heavy chain of Landogrozumab and a Bimagrumab scFv was fused to the C-terminus of the heavy chain of Landogrozumab. The structure of the fusion molecule is shown in Figure 14E (OB362 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 82. The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 91.7 mg / L. The purity before FPLC purification was 96.25 %.

[0654] A truncated form of GHRH (GHRH 1-30) was fused to the N-terminus of the heavy chain of Landogrozumab and a Bimagrumab scFv was fused to the C-terminus of the heavy chain of Landogrozumab. The structure of the fusion molecule is shown in Figure 14F (OB363 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 83. The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 141.0 mg / L. The purity before FPLC purification was 96.15 %.

[0655] A NEP resistant GLP-1 (GLP-1-NEP(R)-204) was fused to the N-terminus of the heavy chain of Landogrozumab and a Bimagrumab scFv was fused to the C-terminus of the heavy chain of Landogrozumab. The structure of the fusion molecule is shown in Figure 141 (OB365 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 106. The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 120.7 mg / L. The purity before FPLC purification was 88.25 %.

[0656] A NEP resistant GLP-1 (GLP-1 -NEP(R)-206) was fused to the N-terminus of the heavy chain of Landogrozumab and a Bimagrumab scFv was fused to the C-terminus of the heavy chain of Landogrozumab. The structure of the fusion molecule is shown in Figure 14J (OB366 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 107. The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 71 .7 mg / L. The purity before FPLC purification was 97.79 %.

[0657] The structure of a fusion molecule having an Anti-activin receptor (Bimagrumab) scFv (form of mini binder) fused to the C-terminus of the heavy chain of Landogrozumab is shown in Figure 14H (OB325 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 76. The sequence of the light chain is set out in SEQ ID NO: 77. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 254.7 mg / L. The purity before FPLC purification was 93.49 %.

[0658] Biological activity was determined using SBE-bla HEK293 reporter cell lines as described in Example 1 .4. All fusion molecules comprising GLP-1 , GLP-I-NEP(R), GIP (1-42), GIP (1-30), GCG, GHRH and GHRH (1-30) peptides are shown to possess the ability to antagonise myostatin (Figure 22).

[0659] GLP-1 R agonism was determined for fusion molecules comprising GLP-1 and NEP resistant GLP-1 (GLP-1 -NEP(R)-204 and GLP-1 -NEP(R)-206; OB365 / OB041 and OB366 / OB041 respectively) using GLP1 R-CRE-bla CHO-K1 reporter cell lines as described in Example 1 .5 (Figure 23A). Next, GLP-1 R agonism was determined for these fusion molecules before and after NEP treatment as described in Example 1.9. Fusion molecules comprising GLP-1 -NEP(R)-204 (QB365 / QB041) were found to show better NEP resistance than Semaglutide, as determined by GLP-1 R agonism after NEP treatment (Figures 23B and 23C).

[0660] GIP-R agonism was determined for fusion molecules comprising GIP (1-42) and GIP (1-30) (OB359 / OB041 and OB360 / OB041 , respectively) using GIPR-CRE-bla HEK 293T cells as described in Example 1.6. In this assay, OB360 / OB041 showed the best biological activity (GIP-R agonism) (Figure 24A).

[0661] Glucagon receptor (GCG-R) agonism was determined for fusion molecules comprising GCG (OB361 / OB041) using GCGR-CRE-bla CHO-K1 cells as described in Example 1 .7. The ability of OB361 / OB041 to agonise GCG-R was demonstrated (Figure 24B).

[0662] GHRH agonism was determined for fusion molecules comprising GHRH and GHRH (1-30) (OB362 / OB041 and OB363 / OB041 respectively) using CHO-K1 GHRHR Gs cells as described in Example 1.8. In this assay, OB363 / OB041 showed the best biological activity (GHRH-R agonism) (Figure 24C).

[0663] 2.9 Obesity-related peptide fused to the C-terminus of the light chain of a myostatin pathway inhibitor antibody with muscle preserving moiety scFv fused to the C-terminus of the heavy chain of the myostatin pathway inhibitor antibody

[0664] An amylin receptor agonist was fused to the C-terminus of the light chain of an anti-myostatin antibody (Landogrozumab), and an Anti-activin receptor (Bimagrumab) scFv (form of mini binder) was fused to the C-terminus of the heavy chain of Landogrozumab. Amylin (GKR) was used for C-terminal amidation. A cleavable linker was used between the C-terminus of Landogrozumab and the amylin receptor agonist peptide. The structure of the fusion molecule is shown in Figure 14G (OB325 / OB364). The sequence of the heavy chain is set out in SEQ ID NO: 76. The sequence of the light chain is set out in SEQ ID NO: 84. The fusion molecule was successfully expressed and purified. The yield after affinity chromatography and FPLC purification was 235.7 mg / L. The purity before FPLC purification was 96.29 %.

[0665] Biological activity is determined using SBE-bla HEK293 and GLP1 R-CRE-bla CHO-K1 reporter cell lines as described in Example 1 .4. Fusion molecules comprising Amylin are shown to possess the ability to antagonise myostatin / activin A inhibition and activate GLP-1 R.

[0666] 2.10 GLP-1 peptide fused to fused to N-terminal of the Heavy chain ofANB-012

[0667] GLP-1 was fused to the N-terminus of the heavy chain of an anti-activin receptor 2B antibody (ANB-012). A 20GS linker was used between the GLP-1 peptide and the antibody. The structure of the fusion molecule is shown in Figure 15A (OB322 / OB223). The sequence of the heavy chain is set out in SEQ ID NO: 85. The sequence of the light chain is set out in SEQ ID NO: 86.

[0668] GLP-1 was fused to the N-terminus of the heavy chain of an anti-activin receptor 2B antibody (ANB-012) and an anti-activin receptor 2B (ANB-012) scFv was fused to the C-terminus of the heavy chain of ANB- 012. A 20GS linker was used between the GLP-1 peptide and the antibody, and between the scFv and the antibody. The structure of the fusion molecule is shown in Figure 15B (OB323 / OB223). The sequence of the heavy chain is set out in SEQ ID NO: 87. The sequence of the light chain is set out in SEQ ID NO: 86.

[0669] GLP-1 was fused to the N-terminus of the heavy chain of an anti-myostatin antibody (Landogrozumab lacking the final K) and an ANB-012 scFv was fused to the C-terminus of the heavy chain of Landogrozumab. A 20GS linker was used between the GLP-1 peptide and the antibody, and a charged linker (KDSSK-10GS-KDSSK; SEQ ID NO: 95) was used between the scFv and the antibody. The structure of the fusion molecule is shown in Figure 15C (OB324 / OB041). The sequence of the heavy chain is set out in SEQ ID NO: 88. The sequence of the light chain is set out in SEQ ID NO: 77.

[0670] The fusion molecules were expressed and purified. Biological activity is determined using SBE-bla HEK293 and GLP1 R-CRE-bla CHO-K1 reporter cell lines as described in Example 1.4. Fusion molecules comprising GLP-1 peptide fused to fused to N-terminal of the Heavy chain of ANB-012 are shown to possess the ability to antagonise myostatin and activate GLP-1 R.

[0671] 2.11 Asymmetric fusion molecules having obesity-related peptides fused to fused to N-terminal of each heavy chain of Landogrozumab

[0672] The structure of a fusion molecule having an anti-activin receptor 2B (ANB-012) scFv (form of mini binder) fused to the C-terminus of the heavy chain of Landogrozumab is shown in Figure 21 A (OB367 / OB368 / OB041). The Landogrozumab Fc region comprises KiH modifications that facilitate pairing of asymmetric heavy chain pairs. The sequence of the first heavy chain (comprising a ‘knob’ mutation) is set out in SEQ ID NO: 101. The sequence of the second heavy chain (comprising a ‘hole’ mutation) is set out in SEQ ID NO: 102. The sequence of the light chain is set out in SEQ ID NO: 77.

[0673] The structure of a fusion molecule having an anti-activin receptor 2B (ANB-012) scFv fused to the C- terminus of the heavy chain of Landogrozumab and obesity-related peptide moieties fused to the N- terminus of each of the constituent heavy chains is shown in Figure 21 B (OB369 / OB370 / OB041). The Landogrozumab Fc region comprises KiH modifications that facilitate pairing of asymmetric heavy chain pairs. GLP-1 is fused to the N-terminus of the first heavy chain (comprising a ‘knob’ mutation) via a 20GS linker and GIP is fused to the N-terminus of the second heavy chain (comprising a ‘hole’ mutation) via a 20GS linker. The sequence of the first heavy chain (comprising a ‘knob’ mutation) is set out in SEQ ID NO: 103. The sequence of the second heavy chain (comprising a ‘hole’ mutation) is set out in SEQ ID NO: 104. The sequence of the light chain is set out in SEQ ID NO: 77.

[0674] The structure of a fusion molecule having an anti-activin receptor 2B (ANB-012) scFv fused to the C- terminus of the heavy chain of Landogrozumab and obesity-related peptide moieties fused to the N- terminus of each of the constituent heavy chains is shown in Figure 21C (OB369 / OB371 / OB041). The Landogrozumab Fc region comprises KiH modifications that facilitate pairing of asymmetric heavy chain pairs GLP-1 is fused to the N-terminus of the first heavy chain (comprising a ‘knob’ mutation) via a 20GS linker and GHRH is fused to the N-terminus of the second heavy chain (comprising a ‘hole’ mutation) via a 20GS linker. The sequence of the first heavy chain (comprising a ‘knob’ mutation) is set out in SEQ ID NO: 103. The sequence of the second heavy chain (comprising a ‘hole’ mutation) is set out in SEQ ID NO: 105. The sequence of the light chain is set out in SEQ ID NO: 77.

[0675] The fusion molecules were expressed and purified. Biological activity is determined using SBE-bla HEK293 and GLP1 R-CRE-bla CHO-K1 reporter cell lines as described in Example 1.4. Asymmetric fusion molecules comprising obesity-related peptide moieties fused to N-terminal of the Heavy chain of Landogrozumab are shown to possess the ability to antagonise myostatin and activate GLP-1 R.

[0676] Example 3: Animal Model Validation

[0677] Diet-Induced Obesity (DIO) Model in C57BL / 6J mice

[0678] 3.1 Objective of model

[0679] The objective of the research is to evaluate the in vivo efficacy of test articles in DIO model in C57BL / 6J mice. DIO stands for Diet-Induced Obesity. The DIO model is a widely used animal model in biomedical research, particularly for studying obesity, diabetes, and related metabolic disorders.

[0680] 3.2 Experimental design

[0681] Male mice on a C57BL / 6J background were fed a high-fat diet (60% kcal from fat, Research Diets D12492) for 20-25 weeks prior to initiating treatment. Body composition was assessed both before the treatment and at the end of the study. Food intake and body weight were recorded every three days. The treatment period lasted for four weeks.

[0682] 3.3 Control groups

[0683] The negative control (vehicle) was treated with Phosphate-Buffered Saline (PBS). The weight loss reference (WL) is the GLP-1 R agonist Dulaglutide. The muscle preservation reference (MP-1) is the anti- activin 2b / 2a receptor antibody Bimagrumab.

[0684] 3.4 Dosage and administration

[0685] The structure of Fusion-001 and Fusion-002 is shown in Figure 12A. Fusion-001 is a GLP-1 receptor agonist fused with anti-activin 2B / 2A receptor antibody (e.g., Bimagrumab) at the N-terminal of the heavy chain. Fusion-002 is a GLP-1 receptor agonist fused with anti-activin 2B / 2A receptor antibody (e.g., Bimagrumab) at the N-terminal of the heavy chain, plus an additional pair of anti-activin 2B / 2A ScFv at the C-terminal of the Fc region of the anti-activin 2B / 2A receptor antibody.

[0686] The negative control, weight loss reference (WL; GLP-1 R agonist, Dulaglutide 4.17 mg / kg, 69.95 nmol / kg), muscle preservation reference 1 (MP-1 ; anti-activin 2b / 2a receptor antibody (Bimagrumab) 10 mg / kg, 69.95 nmol / kg), and two weight loss and muscle preservation reference 1 bispecific fusions (WL.MP-1 Fusion-001 and WL.MP-1 Fusion-002; 10.64 mg / kg, 69.95 nmol / kg and 14.32 mg / kg, 69.95 nmol / kg respectively) were administered via IP (intraperitoneal) injection once a week for 2 weeks. 3.5 Endpoints and measurements

[0687] Body weight and food intake were measured three times per week, while body composition via MRI was measured once at baseline and once at the endpoint. 3.6 Results

[0688] Current research indicates that although the WL reference (Dulaglutide) can effectively reduce body weight, it is accompanied by muscle loss. Fusion-001 and 002 are 5.05 X and 4.46 X stronger in fat mass reduction when compared to MP-1 reference and with comparable activity to WL reference (Figure 12B and Table 4).

[0689] Table 4: Fat mass changes relative to DO. Data are presented as Mean±SEM > n=6 per group. *p<0.05, **p<0.01 , ***p<0.001 , ****p<0.0001 by one-way ANOVA analysis.

[0690] Fusion-1 and 2 reversed lean mass loss (+ 2.3 % and + 5.5 % respectively) triggered by WL reference (- 4.8 %). Fusion-2 showed comparable activity to MP reference (Figure 12C and Table 5).

[0691] Table 5: Lean mass changes relative to DO. Data are presented as Mean±SEM > n=6 per group. *p<0.05, **p<0.01 , ***p<0.001 , ****p<0.0001 by one-way ANOVA analysis. In conclusion, the test articles (two weight loss and muscle preservation reference 1 bispecific fusions; WL.MP-1 Fusion-001 and WL.MP-1 Fusion-002) controlled body weight similarly to the weight loss reference, while also resulting in less muscle loss. After 14 days, Fusion-002 was more effective than double the dose of Fusion-001 for retaining lean body mass (Figure 12D). They are both high-quality body weight loss drugs.

[0692] Example 4: Linker modelling

[0693] This study aimed to determine optimal linkers for connecting the GLP-1 receptor agonist peptide to the myostatin pathway inhibitor. The linker should provide sufficient distance between the two fused peptides to preserve functionality of the components. The linker may also provide additional functionalities such as release of the peptide via a cleavable linker, conferring peptidase resistance to the peptide and / or increasing solubility (via glycosylation).

[0694] Different linkers were incorporated between a GLP-1 peptide moiety and an anti-ACVR2B scFv. Linker sequences are provided in Table 3.

[0695] Table 3: Linkers used in this study.

[0696] Alphafold prediction was conducted to determine the spacing ability of the linkers via looking into the atomic distance between the heavy chain CDR3 and the GLP-1 peptides. A larger atomic distance indicates a better domain separation ability of the linkers.

[0697] The results are shown in Figure 13A. The relative distance between GLP-1 Peptide to the H-CDR3 of the anti ACVR2B scFv for the selected linkers is shown in Figure 13B. Some linkers confers additional biological functionalities such as protease resistance (peptide protection linker), peptide release (HCG- CTP-CL), half-life extension via glycosylation (HCG-CTP) and solubility enhancement (HCG-CTP and Ser-rich linkers). Additional 2 amino acid PG were included at the connecting interface of the scFv and the linkers to facilitate formation of a turn conformation that encourage the separation of the peptide from the scFv.

[0698] Example 5: Antibody-peptide conjugates 5.1 Development of myostatin pathway inhibitors for conjugation

[0699] As a proof of concept, Bimagrumab mutants were generated with a E380C mutation site for peptide conjugation. The amino acid sequence of the heavy chain of the E380C mutant is set out in SEQ ID NO: 89. The amino acid sequence of the light chain (lambda) of the E380C mutant is set out SEQ ID NO: 90.

[0700] Next, the activity of the E380C mutant was tested and compared to Bimagrumab (wild-type) during myostatin stimulation and Activin A stimulation using the SBE-bla HEK293 reporter cell line. Figure 16A shows that the E380C mutant has a comparable response to myostatin stimulation compared to Bimagrumab. Figure 16B shows that the E380C mutant has a comparable response to Activin A stimulation compared to Bimagrumab.

[0701] A murinized Bimagrumab was also developed for conjugation by obesity-related peptides. The amino acid sequence of the heavy chain having a mouse IgG 1 Fc is set out in SEQ ID NO: 91 . The amino acid sequence of the human / mouse chimeric light chain (kappa) is set out in SEQ ID NO: 93. Murinized Bimagrumab mutants having a mutation site for peptide conjugation were also developed. The Bimagrumab heavy chain Fc was swapped for a mouse IgG 1 Fc having a Q382C mutation for peptide conjugation. The amino acid sequence of the heavy chain of the Q382C mutant is set out in SEQ ID NO: 92.

[0702] The biological activity of Biamgrum...

Claims

1. Claims:1 . A fusion molecule comprising an obesity-related peptide moiety, fused to a myostatin pathway inhibitor moiety.

2. The fusion molecule of claim 1 , wherein the obesity-related peptide moiety is a Glucagon-like peptide 1 (GLP-1) receptor agonist moiety.

3. The fusion molecule of claim 2, wherein: the GLP-1 receptor agonist moiety is, or comprises, a peptide, polypeptide or polypeptide complex; and / or the myostatin pathway inhibitor moiety is, or comprises, a peptide, polypeptide or polypeptide complex.

4. The fusion molecule of claim 1 , wherein the obesity-related peptide moiety is a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon (GCG) receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist.

5. The fusion molecule according to any one of claims 1 to 4, wherein the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule that binds to a myostatin pathway protein, optionally wherein the myostatin pathway protein is myostatin, ActRIIA, ActRIIB, ActRIIA and ActRIIB, Activin A, ALK4 or ALK5.

6. The fusion molecule according to any one of claims 1 to 5, wherein the obesity-related peptide moiety is directly fused to the myostatin pathway inhibitor moiety.

7. The fusion molecule according to any one of claims 1 to 6, wherein the obesity-related peptide moiety is fused to the myostatin pathway inhibitor moiety via a linker.

8. The fusion molecule of claim 7, wherein the linker is a cleavable linker, optionally a protease- cleavable linker.

9. The fusion molecule according to any one of claims 1 to 8, further comprising a musclepreserving moiety.

10. The fusion molecule of claim 9, wherein the muscle-preserving moiety is, or comprises, a myostatin pathway inhibitor.11 . The fusion molecule of claim 9 or claim 10, wherein the muscle-preserving moiety is, or comprises, an antibody-derived target-binding molecule, optionally a VHH or scFv.

12. The fusion molecule of any one of claims 9 to 11 , wherein the myostatin pathway inhibitor moiety is, or comprises, an antibody that binds to a myostatin pathway protein, and wherein the muscle-preserving moiety is fused to the C-terminus of a constituent polypeptide of the antibody that binds to a myostatin pathway protein.

13. The fusion molecule according to any one of claims 1-10, further comprising a second obesity- related peptide moiety.

14. The fusion molecule according to claim 13, wherein the fusion molecule comprises, or consists of: i) a Glucagon-like peptide 1 (GLP-1) receptor agonist moiety; ii) an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist; and iii) a myostatin pathway inhibitor moiety.

15. The fusion molecule according to any one of claims 2 to 14, wherein the myostatin pathway inhibitor moiety is, or comprises, a peptide, polypeptide or polypeptide complex, and wherein the C- terminus of the obesity-related peptide moiety is fused to the myostatin pathway inhibitor moiety peptide, polypeptide or to a constituent polypeptide of the myostatin pathway inhibitor moiety polypeptide complex.

16. The fusion molecule according to any one of claims 2 to 15, wherein the myostatin pathway inhibitor moiety is, or comprises, a peptide, polypeptide or polypeptide complex, and wherein the obesity- related peptide moiety is fused to the N-terminus of the myostatin pathway inhibitor moiety peptide or polypeptide, or to the N-terminus of a constituent polypeptide of the myostatin pathway inhibitor moiety polypeptide complex.

17. The fusion molecule according to any one of claims 3 to 16, wherein the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule comprising an antibody heavy chain, and wherein the obesity-related peptide moiety is fused to the N-terminus of the antibody heavy chain.

18. The fusion molecule according to any one of claims 3 to 17, wherein the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule comprising an antibody light chain, and wherein the obesity-related peptide moiety is fused to the N-terminus of the antibody light chain.

19. The fusion molecule according to any one of claims 3 to 18, wherein the myostatin pathway inhibitor moiety is, or comprises, an antigen-binding molecule comprising an antibody light chain, and wherein the obesity-related peptide moiety is fused to the C-terminus of the antibody light chain.

20. The fusion molecule according to any one of claims 3 to 14, wherein the obesity-related peptide moiety is chemically conjugated to the myostatin pathway inhibitor moiety.21 . The fusion molecule according to claim 20, wherein the obesity-related peptide moiety is chemically conjugated to the myostatin pathway inhibitor moiety via cysteine-based conjugation, optionally via a chemical linker comprising a maleimide or bromo-acetamide group.

22. The fusion molecule according to any one of claim 20 or claim 21 , wherein the myostatin pathway inhibitor moiety is, or comprises, an antibody, wherein the obesity-related peptide moiety is chemically conjugated to the CH2 region of the antibody.

23. The fusion molecule according to any one of claims 2 to 22, wherein the GLP-1 receptor agonist moiety comprises, or consists of, an amino acid sequence having at least 70% amino acid sequence identity to SEQ ID NO: 2.

24. The fusion molecule according to any one of claims 1 to 23, wherein the myostatin pathway inhibitor moiety is an inhibitor of myostatin, ActRIIA, ActRIIB, ActRIIA and ActRIIB, Activin A, ALK4 or ALK5.

25. The fusion molecule according to any one of claims 1 to 24, wherein the myostatin pathway inhibitor moiety is, or comprises, Apitegromab, GYM329, Taldefgrobep alfa, KER-065, Trevogrumab, Garetosmab, Bimagrumab (BYM338), and BIO101 (20-hydroxyecdysone).

26. A polynucleotide, or plurality of polynucleotides, encoding the fusion molecule according to any one of claims 1 to 25.

27. A pharmaceutical composition comprising a fusion molecule according to any one of claims 1 to25, and a pharmaceutically acceptable carrier, diluent, excipient or adjuvant.

28. A fusion molecule according to any one of claims 1 to 25, a polynucleotide or plurality of polynucleotides according to claim 26, or a pharmaceutical composition according to claim 27, for use in a method of treating or preventing a disease or condition.

29. A method of treating or preventing a disease or condition, comprising administering a fusion molecule according to any one of claims 1 to 25, a polynucleotide according to claim 26, or a pharmaceutical composition according to claim 27, to a patient in need thereof.

30. The fusion molecule for use according to claim 28 or the method according to claim 29, wherein the disease or condition is obesity, insulin dependent diabetes mellitus or non-insulin dependent diabetes mellitus.

31. A method of treating obesity, comprising administering a fusion molecule comprising (i) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide or polypeptide; and / or (ii) an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylinreceptor agonist, or a Peptide YY (PYY) agonist; fused to (iii) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor is antigen-binding molecule.

32. A fusion molecule comprising (i) a GLP-1 receptor agonist moiety, wherein the GLP-1 receptor agonist moiety is a peptide or polypeptide; and / or (ii) an obesity-related peptide moiety selected from a Growth Hormone Releasing Hormone (GHRH) agonist, a gastric inhibitory peptide (GIP) receptor agonist or antagonist, a glucagon receptor agonist, an Amylin receptor agonist, or a Peptide YY (PYY) agonist; fused to (iii) a myostatin pathway inhibitor moiety, wherein the myostatin pathway inhibitor is an antigenbinding molecule; for use in a method of treating obesity.

Images