Combination therapy with actriib receptor variants and GLP-1 agonists

Abstract

The present disclosure provides combinations of TGFβ superfamily ligand binding agents and GLP-1 agonists, compositions thereof, and methods of use in the treatment of metabolic disorders.

Description

[0001] Attorney Docket No.35PH-005 / 03WO 349552-2048 COMBINATION THERAPY WITH ACTRIIB RECEPTOR VARIANTS AND GLP-1 AGONISTS CROSS-REFERENCE TORELATEDAPPLICATIONS[1] This application is an international PCT application claiming priority to US Provisional Application No. 63 / 581,428, filed on September 8, 2023; US Provisional Application No. 63 / 647,506, filed on May 14, 2024; and US Provisional Application No. 63 / 678,479, filed on August 1, 2024, the contents of each are incorporated herein by reference in their entireties. REFERENCE TO ANELECTRONICSEQUENCELISTING[2] The contents of the electronic sequence listing (35PH_005_03WO_SeqList_ST26.xml; Size: (451,034 bytes; and Date of Creation: September 4, 2024) are herein incorporated by reference in its entirety. FIELD[3] The present disclosure relates to combinations of E<;a WYUKVLGROQ] QOMGSJ HOSJOSM agents and GLP-1 agonists and uses thereof for the treatment of metabolic disorders. BACKGROUND[4] Treatment of metabolic disorders such as obesity remains elusive as the regulation of metabolism and fat storage involves complex biological feedback systems. To date, drugs effective in regulating metabolic dysfunction often exhibit several side effects, which limit their usefulness in patient populations, and in particular, in obese patient populations, who may require long term treatment. Thus, there is a need for additional compositions and methods to treat metabolic disorders including obesity. SUMMARY [5] In some embodiments, the present disclosure provides a combination comprising a E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX ITRUVOWOSM (a) a first polypeptide and a second polypeptide, wherein the first and second polypeptides each comprise: (i) a polypeptide comprising an amino acid sequence that is at least 90% identical to an Activin receptor type IIB (ActRIIB) ectodomain (ECD) variant, the ActRIIB ECD variant comprising an amino acid substitution at the position corresponding to position 33 of SEQ ID NO: 2; (ii) an Fc domain monomer; and (iii) a peptide linker joining the polypeptide to the Fc domain monomer; and (b) a Glucagon-like peptide 1 (GLP-1) agonist. The combination of claim 1, wherein the ActRIIB Attorney Docket No.35PH-005 / 03WO 349552-2048 ECD variant demonstrates reduced inhibition of BMP-9 and / or BMP-10 compared to a wild- type ActRIIB ectodomain. In some embodiments, the amino acid substitution is selected from L33F, L33Q, L33Y, L33W, L33H, L33R, L33E, L33K, and L33M. [6] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33F. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 10; or comprises or consists of the amino acid sequence of SEQ ID NO: 10. [7] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33Q. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 11; or comprises or consists of the amino acid sequence of SEQ ID NO: 11. [8] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33Y. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 12; or comprises or consists of the amino acid sequence of SEQ ID NO: 12. [9] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33W. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 13; or comprises or consists of the amino acid sequence of SEQ ID NO: 13.

[0010] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33H. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 14; or comprises or consists of the amino acid sequence of SEQ ID NO: 14.

[0011] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33R. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 15; or comprises or consists of the amino acid sequence of SEQ ID NO: 15.

[0012] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33E. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that Attorney Docket No.35PH-005 / 03WO 349552-2048 is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 16; or comprises or consists of the amino acid sequence of SEQ ID NO: 16.

[0013] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33K. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 17; or comprises or consists of the amino acid sequence of SEQ ID NO: 17.

[0014] In some embodiments, the ActRIIB ECD variant comprises the amino acid substitution L33M. In some embodiments, the ActRIIB ECD variant comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 18; or comprises or consists of the amino acid sequence of SEQ ID NO: 18.

[0015] In some embodiments, the ActRIIB ECD variant further comprises an amino acid substitution at position 27 of SEQ ID NO: 2. In some embodiments, the ActRIIB ECD variant further comprises an amino acid substitution at position 69 of SEQ ID NO: 2. In some embodiments, the ActRIIB ECD variant further comprises one or more amino acid substitutions which is G27D, G27E, T69E, T69Q, or T69H.

[0016] In some embodiments, the ActRIIB ECD variant further comprises one or more additional amino acids at the N or C terminus. In some embodiments, the ActRIIB ECD variant further comprises the following amino acids at the N terminus: GRGEA (SEQ ID NO: 63) and / or the following amino acids at the C-terminus: APT.

[0017] In some embodiments, the first and the second polypeptides comprise the following structure, from N- to C-terminus: ActRIIB-ECD – peptide linker – Fc domain monomer.

[0018] In some embodiments, the Fc domain monomer is an IgG1, IgG2, IgG3 or IgG4 isotype. In some embodiments, the Fc domain monomer is a human Fc domain monomer or a murine Fc domain monomer. In some embodiments, the Fc domain monomer is engineered to reduce aggregation or to modulate stability of a dimer of the polypeptide. In some embodiments, the Fc domain monomer comprises the amino acid substitutions of M252Y, S254T, and T256E (YTE). In some embodiments, the Fc domain monomer comprises the M252Y amino acid substitution. In some embodiments, the Fc domain monomer includes a D at position 356 and an L at position 358 (DL). In some embodiments, the Fc domain monomer includes an E at position 356 and an M at position 358 (EM). In some embodiments, the Fc domain monomer further comprises a Lysine residue (K) at the C terminus. In some Attorney Docket No.35PH-005 / 03WO 349552-2048 embodiments, the Fc domain monomer comprises an amino acid sequence that is at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to any one of SEQ ID NOs: 252-292; or comprises or consists of an amino acid sequence selected from any one of SEQ ID NOs: 252-292. In some embodiments, the Fc domain monomer is an IgG1 isotype. In some embodiments, the Fc domain monomer comprises or consists of the amino acid sequence set forth in SEQ ID NO: 253, SEQ ID NO: 255, or SEQ ID NO: 256. In some embodiments, the Fc domain monomer in the first polypeptide forms a dimer with the Fc domain monomer in the second polypeptide.

[0019] In some embodiments, the peptide linker is Glycine-rich. In some embodiments, the peptide linker is between 10 and 40 amino acids long. In some embodiments, the peptide linker is at least 10 amino acids long, at least 14 amino acids long, at least 19 amino acids long, or at least 39 amino acids long. In some embodiments, the peptide linker is 10 amino acids long, 14 amino acids long, 19 amino acids long, or 39 amino acids long. In some embodiments, the peptide linker comprises the amino acid sequence set forth in any one of SEQ ID NOs: 89, 94, or 98.

[0020] In some embodiments, the ActRIIB-ECD comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to any one of SEQ ID NOs:4-62; or comprises or consists of an amino acid sequence selected from any one of SEQ ID NOs: 4-62. In some embodiments, the ActRIIB-ECD comprises or consists of the amino acid sequence of SEQ ID NO: 10-18, or a sequence at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto. In some embodiments, the ActRIIB-ECD comprises or consists of the amino acid sequence of SEQ ID NO: 13 or a sequence at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto.

[0021] In some embodiments, the first and / or second polypeptide: comprise an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to an amino acid sequence selected from SEQ ID NOs: 174-251; or comprise or consist of an amino acid sequence selected from SEQ ID NOs: 174-251.

[0022] In some embodiments, the first and / or second polypeptide: comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to an amino acid sequence selected from SEQ ID NOs: 175, 176, 180, 204-214, and 230-234; or comprises or consists of an amino acid sequence selected from SEQ ID NOs: 175, 176, 180, 204-214, and 230-234. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0023] In some embodiments, the first and / or second polypeptide: comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to an amino acid sequence selected from SEQ ID NOs: 211 and 230-234; or comprises or consists of an amino acid sequence selected from SEQ ID NOs: 211 and 230-234.

[0024] In some embodiments, the first and / or second polypeptide: comprises or consists of the amino acid sequence of SEQ ID NO: 231, or an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical thereto; or comprises or consists of the amino acid sequence of SEQ ID NO: 231.

[0025] In some embodiments, the first and / or second polypeptide comprises or consists of the amino acid sequence of SEQ ID NO: 234, or an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical thereto; or comprises or consists of the amino acid sequence of SEQ ID NO: 234.

[0026] In some embodiments, the first and / or second polypeptide further comprise an albumin-binding domain, a fibronectin domain, or a human serum albumin domain fused to the N- or C-terminus of the ActRIIB-ECD via a linker. In some embodiments, the first and / or second polypeptide further comprises a signal peptide of SEQ ID NO: 1 at the N-terminus of the ActRIIB-ECD. In some embodiments, the signal peptide is cleaved from the mature protein.

[0027] In some embodiments, the binding agent is conjugated with a targeting agent, a therapeutic moiety, a detectable moiety, or a diagnostic moiety. In some embodiments, the targeting agent, the therapeutic moiety, the detectable moiety, or the diagnostic moiety comprises an antibody or antigen binding fragment thereof, a binding agent having affinity for GSTXNKV RKRHKV TL XNK E<;a WYUKVLGROQ] TV LTV GSTXNKV XNKVGUKYXOI XGVMKX' G VGJOTXNKVGU] agent, an imaging agent, a fluorescent moiety, a cytotoxic agent, an anti-mitotic drug, a nanoparticle-based carrier, a polymer-conjugated drug, a nanocarrier, an imaging agent, a stabilizing agent, a drug, a nanocarrier, or a dendrimer.

[0028] In some embodiments, the first and second polypeptides form a dimer linked by at least one disulfide bond between the Fc domain monomer of the first polypeptide and the Fc domain monomer of the second polypeptide. In some embodiments, the binding agent: demonstrates similar or increased binding to human activin A, activin B, GDF-8, and / or GDF- 11 and demonstrates reduced binding to human BMP-9 and / or BMP-10 compared to a polypeptide comprising a WT ActRIIB-ECD; does not substantially bind to human BMP-9; demonstrates reduced binding to human BMP-10 compared to a polypeptide comprising a WT Attorney Docket No.35PH-005 / 03WO 349552-2048 ActRIIB-ECD; inhibits signaling of one or more of human activin A, activin B, GDF-8, and GDF-11; and / or does not substantially inhibit human BMP-9 and / or BMP-10 signaling.

[0029] In some embodiments, the GLP-1 agonist is an antibody, small molecule, peptide, or aptamer. In some embodiments, the GLP-1 agonist is selected from the group consisting of exenatide, exenatide extended-release, efpeglenatide, dulaglutide, liraglutide, lixisenatide, lotiglipron, semaglutide, tirzepatide, cotadutide, noiiglutide, oxyntomodulin, orforglipron, retatrutide, albiglutide, beinaglutide and PEG-loxenatide, pemvidutide, and danuglipron. In some embodiments, the GLP-1 agonist is selected from semaglutide and tirzepatide. In some embodiments, the GLP-1 agonist is a dual GLP-1 agonist and GIP agonist, a dual GLP-1 agonist and GCG agonist, or a triagonist of GIP / GLP-1 / glucagon receptors.

[0030] In some embodiments, the binding agent and GLP-1 agonist are formulated in separate pharmaceutical compositions. In some embodiments, the binding agent and GLP-1 agonist are formulated in the same pharmaceutical composition. In some embodiments, the pharmaceutical composition is formulated for administration by injection or infusion. In some embodiments, the composition is formulated for intravenous, subcutaneous, intraperitoneal, or intramuscular administration.

[0031] In some embodiments, the present disclosure provides a kit comprising a combination described herein, and optionally, directions for use.

[0032] In some embodiments, the present disclosure provides a method of treating or preventing a metabolic disease or condition in a subject in need thereof, the method comprising administering a combination described herein to the subject. In some embodiments, the subject is a human. In some embodiments, the metabolic disorder is selected from the group consisting of obesity, diabetes, metabolic syndrome, anti-psychotic drug-associated obesity, glucocorticoid-induced obesity, hypothalamic obesity associated with craniopharyngioma, Prader-Willi syndrome, and a monogenetic disorder associated with obesity such as Bardet- Biedl syndrome. In some embodiments, the metabolic disorder is selected from obesity, Type 2 diabetes, and pre-diabetes. In some embodiments, the metabolic disorder is obesity.

[0033] In some embodiments, the method does not: cause a vascular complication in a subject; increase vascular permeability or leakage in a subject; increase red blood cell mass; increase hemoglobin; cause thrombocytopenia; cause a hematological complication in a subject; and / or does not cause a reduction in lean muscle mass in the subject. In some embodiments, the Attorney Docket No.35PH-005 / 03WO 349552-2048 treatment increases lean mass in the subject. In some embodiments, the treatment reduces fat mass in the subject.

[0034] Further scope, applicability and advantages of the present technology will become apparent from the non-restrictive detailed description given hereinafter. It should be understood, however, that this detailed description, while indicating exemplary embodiments of the technology, is given by way of example only, with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] For a better understanding of the technology and to show more clearly how it may be carried into effect, reference will now be made by way of example to the accompanying drawings, which illustrate aspects and features according to non-limiting embodiments of the present technology.

[0036] FIGs. 1A and 1B show polyacrylamide gel electrophoresis analysis under non- reducing and reducing conditions of representative ActRIIB-ECD polypeptide constructs. 6LXKV K\UVKWWOTS GSJ UYVOLOIGXOTS' + cM TL KGIN UVTXKOS [GW QTGJKJ TS XNK MKQ' GW OSJOIGXKJ4 A1 / 4 Protein 75; P739: Protein 739; P750: Protein 750; P751: Protein 751; P753: Protein 753; P754: Protein 754; P1182: Protein 1182; P1185: Protein 1185; P1229: Protein 1229; P1371: Protein 1371; P1372: Protein 1372; P1373: Protein 1373; P1374: Protein 1374; P1375: Protein 1375; P1389: Protein 1389; P1406: Protein 1406; P1409: Protein 1409. “NR”: non-reducing conditions; “R”: reducing conditions.

[0037] FIG.2A – FIG.2Q show comparative charts (radar plots) in which IC50 values for SKYXVGQO^GXOTS TL E<;a WYUKVLGROQ] QOMGSJW $GIXOZOS 6' GIXOZOS 7' <9;-8, GDF-11, BMP-9, and BMP-10) are displayed for exemplary test proteins, as indicated. Points at the center of the chart indicate low neutralization potency for a given cytokine (high IC50 value), whereas points at the edge of the chart indicate high neutralization potency for a given cytokine (low IC50 value). Exemplary test proteins displayed are (FIG. 2A) P739, P750, and P751, (FIG. 2B) P753, P754, and P1229, (FIG. 2C) P1373, P1371, and P1375, (FIG. 2D) P1182 and P1185, and (FIG. 2E) P1389, P1406, and P1409. All agents are compared to wild type ActRIIB-ECD (P75). FIG. 2F - FIG. 2I show representative results in the HEK-Blue cell- based assay for inhibition of activin A, activin B, GDF-8, and GDF-11, respectively, for exemplary proteins P75, P1229, P1371, P1372, P1373, P1374, and P1375. FIG.2J - FIG.2K show representative results in the HepG2 cell-based assay for inhibition of BMP-9 and BMP- Attorney Docket No.35PH-005 / 03WO 349552-2048 10, respectively, for exemplary proteins P75, P1229, P1372, P1373, P1374, and P1375. FIG. 2L - FIG.2O show representative results in the HEK-Blue cell-based assay for inhibition of activin A, activin B, GDF-8, and GDF-11, respectively, for exemplary proteins P75, P1229, P1373, P1483, P1484, P1485, and P1486. FIG. 2P - FIG.2Q show representative results in the HepG2 cell-based assay for inhibition of BMP-9 and BMP-10, respectively, for exemplary proteins P75, P1229, P1373, P1483, P1484, P1485, and P1486. Error bars indicate standard error of the mean (SEM).

[0038] FIG. 3 shows results from the activin A ELISA using supernatants from the small- scale production of ActRIIB-ECD fusion proteins. Results are expressed as a % of the signal obtained with wild-type ActRIIB-ECD-Fc (P75). In this assay, a loss of signal suggests increased binding of the exemplary test agent to activin A. Error bars indicate standard error of the mean (SEM). This graph was generated using GraphPad Prism 9.0.

[0039] FIG.4 shows results from the BMP-9 ELISA using supernatants from the small-scale production of ActRIIB-ECD fusion proteins. Results are expressed as a % of the signal obtained with wild-type ActRIIB-ECD-Fc (P75). In this assay, a loss of signal suggests decreased binding of the exemplary test agent to BMP-9. Error bars indicate standard error of the mean (SEM). This graph was generated using GraphPad Prism 9.0.

[0040] FIG.5A – FIG.5B show results from the BMP-10 assays using supernatants from the small-scale production of ActRIIB-ECD fusion proteins. (FIG.5A) Results from the cell-based assays are expressed as a % of the signal obtained with BMP-10 alone. In this assay, a loss of signal suggests increased binding of the exemplary test agent to BMP-10. Error bars indicate standard error of the mean (SEM). (FIG.5B) Bio-layer interferometry was used to derive KD values for exemplary test agents. These graphs were generated using GraphPad Prism 9.0.

[0041] FIG.6 shows results from single-injection experiments in wild-type mice. Male mice were injected with a single dose of test agent as indicated (25 mg / kg, subcutaneous), and body weight gain was evaluated after 4 days. Results were normalized to the vehicle control, and error bars indicate standard error of the mean (SEM). Results were analyzed by one-way ANOVA followed by post-hoc Bonferroni-corrected multiple comparison test; *p<0.05, **p<0.01, ***p<0.001, ***p<0.0001 relative to the vehicle group.

[0042] FIG.7A – FIG.7B show body weight gain in male mice injected (subcutaneous) with test proteins. FIG.7A shows results for P750 (1, 5, or 25 mg / kg) and FIG.7B shows results for P1229 (5 or 25 mg / kg) and P75 (25 mg / kg). Injections were performed twice weekly for 11 Attorney Docket No.35PH-005 / 03WO 349552-2048 days (P750) or 7 days (P1229 and P75). Results were normalized to the vehicle control, and error bars indicate standard error of the mean (SEM). Results were analyzed by two-way ANOVA followed by post-hoc Bonferroni-corrected multiple comparison test; *p<0.05, ***p<0.001, ***p<0.0001 relative to the vehicle group.

[0043] FIG.8 provides an exemplary schematic of binding agents described herein.

[0044] FIG.9A – FIG.9D illustrate changes in skeletal muscle mass after a week of treatment with vehicle, P1229 (5 or 25 mg / kg), and P75 (25 mg / kg). Injections were done subcutaneously, twice weekly. FIG.9A shows average tibialis anterior weight. FIG.9B shows tibialis weight as normalized to vehicle control. FIG.9C shows average gastrocnemius weight. FIG.9D shows gastrocnemius weight as normalized to vehicle control. Results were analyzed by one-way ANOVA followed by post-hoc Bonferroni-corrected multiple comparison test; *p<0.05, ***p<0.001 relative to the vehicle group.

[0045] FIG. 10 illustrates changes in Mss51 expression in tibialis anterior after a week of treatment with vehicle, P1229 (5 or 25 mg / kg), and P75 (25 mg / kg). Injections were done subcutaneously, twice weekly. Results were analyzed by one-way ANOVA followed by post- hoc Bonferroni-corrected multiple comparison test; ****p<0.0001 relative to the vehicle group.

[0046] FIG. 11A – FIG. 11F illustrate changes in body composition of diet-induced obese (DIO) mice injected subcutaneously with vehicle, P1229 (25 mg / kg, twice weekly), P75 (25 mg / kg, twice weekly), P1373 (5, 20, or 50 mg / kg twice weekly), or P1307 (CDD866, murine bimagrumab (an antibody targeting ActRIIB and ActRIIA), 20 mg / kg once weekly). FIGs. 11A and 11D show average lean mass, FIG.11B and 11E show average fat mass, and FIG. 11C and 11F show the ratio of lean mass over fat mass. Parameters were assessed by echoMRI. Results were analyzed by one-way ANOVA followed by post-hoc Bonferroni-corrected multiple comparison test; *p<0.05 relative to the vehicle group.

[0047] FIG. 12A – FIG. 12B illustrate food consumption over time of DIO mice injected subcutaneously with vehicle, P1229 (25 mg / kg, twice weekly), P75 (25 mg / kg, twice weekly), P1373 (5, 20, or 50 mg / kg twice weekly), or P1307 (CDD866, or murine bimagrumab, 20 mg / kg once weekly). FIGs.12C-H show skeletal muscle weights at the end of the study; FIG. 12C – FIG. 12D, FIG. 12E – FIG. 12F, and FIG. 12G – FIG. 12H show tibialis anterior, gastrocnemius, and soleus weights, respectively. Results were analyzed by one-way ANOVA Attorney Docket No.35PH-005 / 03WO 349552-2048 followed by post-hoc Bonferroni-corrected multiple comparison test; *p<0.05, **p<0.01 relative to the vehicle group.

[0048] FIG. 13A – FIG. 13C illustrate changes in skeletal muscle gene expression in DIO mice after 3 weeks of subcutaneous injections with vehicle, P1229 (25 mg / kg, twice weekly), P75 (25 mg / kg, twice weekly), P1373 (5, 20, or 50 mg / kg twice weekly), or P1307 (CDD866, or murine bimagrumab, 20 mg / kg once weekly). FIG. 13A – FIG. 13B illustrate Mss51 expression in gastrocnemius muscle. FIG.13C illustrates changes in the ratio of Serpine1 to Id1 expression ratio in soleus muscle. Results were analyzed by one-way ANOVA followed by post-hoc Bonferroni-corrected multiple comparison test; *p<0.05, **p<0.01, ***p<0.001 relative to the vehicle group.

[0049] FIG.14A – FIG.14F illustrate changes in hepatic gene expression in DIO mice after subcutaneous injections with vehicle, P1229 (25 mg / kg, twice weekly), P75 (25 mg / kg, twice weekly), P1373 (5, 20, or 50 mg / kg twice weekly), or P1307 (CDD866, or murine bimagrumab, 20 mg / kg once weekly). FIG. 14A – FIG. 14B show Ahsg gene expression, encoding for fetuin-A. FIG.14C – FIG.14D show Fgf21 gene expression, encoding for FGF21. FIG.14E – FIG. 14F Show Inhbe gene expression, encoding for activin E. Results were analyzed by one-way ANOVA followed by post-hoc Bonferroni-corrected multiple comparison test; *p<0.05, **p<0.01, ***p<0.001 relative to the vehicle group.

[0050] FIG. 15A – FIG. 15B illustrate changes in follicle-stimulating hormone (FSH) production in DIO mice after subcutaneous injections with vehicle, P1229 (25 mg / kg, twice weekly), P75 (25 mg / kg, twice weekly), P1373 (5, 20, or 50 mg / kg twice weekly), or P1307 (CDD866, or murine bimagrumab, 20 mg / kg once weekly). Results were analyzed by one-way ANOVA followed by post-hoc Bonferroni-corrected multiple comparison test; ***p<0.001, ****p<0.0001 relative to the vehicle group.

[0051] FIG. 16A – FIG. 16E illustrate changes in body weight and body composition (assessed by NMR) in DIO mice after subcutaneous injections with vehicle, P1229 (10 or 40 mg / kg, twice weekly), P1307 (CDD866, 20 mg / kg weekly), semaglutide (40 cM)PM' JGOQ]%' XOV^KUGXOJK $. / cM)PM' JGOQ]%' A+,,3 $.* RM)PM% & WKRGMQYXOJK' A+,,3 $.* RM)PM% & XOV^KUGXOJK' TV A+,,3 $.* RM)PM% & IGQTVOI VKWXVOIXOTS( CKWYQXW [KVK GSGQ]^KJ H] two-way ANOVA followed by post-hoc Tukey-corrected multiple comparison test; *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001. Statistical significance is only shown for D21 data. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0052] FIG.17A – FIG.17G illustrate organ weights at the end of the study (D21) in DIO mice after subcutaneous injections with vehicle, P1229 (10 or 40 mg / kg, twice weekly), P1307 (CDD866, 20 mg / kg weekly), semaglutide (40 cM)PM' JGOQ]%' XOV^KUGXOJK $. / cM)PM' JGOQ]%' A+,,3 $.* RM)PM% & WKRGMQYXOJK' A+,,3 $.* RM)PM% & XOV^KUGXOJK' TV A+,,3 $.* RM)PM% & caloric restriction. Results were analyzed by one-way ANOVA followed by post-hoc Tukey- corrected multiple comparison test; *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001. All groups were compared to the vehicle group, and incretin mimetics alone were compared to their respective combination group with P1229.

[0053] FIG.18A – FIG. 18B illustrate weight and body composition changes in mice after subcutaneous injections with the indicated compounds. FIG. 18A shows total weight loss. FIG.18B shows changes and fat mass and lean muscle mass.

[0054] FIG. 19 shows activity of ligand trap and GLP-1 RA in comparison to the coformulation of the ligand trap and GLP-1 RA.

[0055] FIG. 20A illustrates body weight changes in mice following a single subcutaneous injection of P1229 (50 mg / kg), semaglutide (2 mg / kg), or a co-formulation of P1229 (50 mg / kg) and semglutide (2 mg / kg). FIG.20B – FIG.20C illustrate pharmacokinetic profiles of semaglutide and P1229 in these animals. FIG. 20D illustrates the changes in circulating follicle-stimulating hormone (FSH) over the course of the study. FSH values are expressed as % baseline. Arrow indicates the onset of treatment. DETAILED DESCRIPTION Overview

[0056] The UVKWKSX JOWIQTWYVK UVTZOJKW ITRHOSGXOTSW TL E<;a WYUKVLGROQ] QOMGSJ HOSJOSM agents and GLP-1 agonists, compositions thereof, and methods of use in the treatment of RKXGHTQOI JOWTVJKVW( =S WTRK KRHTJORKSXW' E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX GSJ <>A- 1 agonist are formulated in the same composition. In some embodiments, administration of a binding agent described herein and a GLP-1 agonist exhibits a beneficial effect, wherein administration of the binding agent decreases the dosage of a GLP-1 agonist required to see an effect, and / or increases the therapeutic effect of the GLP-1 agonist, relative to administration of the GLP-1 agonist alone. In some embodiments, a beneficial effect is demonstrated wherein a GLP-1 agonist decreases the dosage of the binding agent required to see an effect, and / or increases the therapeutic effect of the binding agent, relative to administration of the binding agent alone. In some embodiments, the beneficial effect is increased safety of the combination Attorney Docket No.35PH-005 / 03WO 349552-2048 relative to a binding agent or a GLP-1 agonist alone. In some embodiments, the beneficial effect is increased efficacy of the combination relative to a binding agent or a GLP-1 agonist alone. In some embodiments, the beneficial effect is increased tolerability relative to a binding agent or a GLP-1 agonist alone. In some embodiments, the beneficial effect is reduced undesirable side effects relative to a binding agent or a GLP-1 agonist alone.

[0057] The present technology is explained in greater detail below. This description is not intended to be a detailed catalog of all the different ways in which the technology may be implemented, or all the features that may be added to the instant technology. For examples, features illustrated with respect to one embodiment may be incorporated into other embodiments, and features illustrated with respect to a particular embodiment may be deleted from that embodiment. In addition, numerous variations and additions to the various embodiments suggested herein will be apparent to those skilled in the art in light of the instant disclosure, which variations and additions do not depart from the present technology. Hence, the following description is intended to illustrate some particular embodiments of the technology, and not to exhaustively specify all permutations, combinations and variations thereof. Definitions

[0058] In order to provide a clear and consistent understanding of the terms used in the present specification, a number of definitions are provided below. Moreover, unless defined otherwise, all technical and scientific terms as used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention pertains.

[0059] The use of the terms “a” and “an” and “the” when used in conjunction with the term “comprising” in the claims and / or the specification may mean “one”, but it is also consistent with the meaning of “one or more”, “at least one”, and “one or more than one”. Similarly, the term “another” may mean at least a second or more. These terms are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0060] As used herein, the terms “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “include” and “includes”) or “containing” (and any form of containing, such as “contain” and “contains”), are inclusive or open-ended and do Attorney Docket No.35PH-005 / 03WO 349552-2048 not exclude additional, unrecited elements or process steps. The term “consisting of” is to be construed as close-ended.

[0061] The term “about” is used to indicate that a value or quantity refers to the actual given value and also the approximation of such given value that would reasonably be inferred based on the ordinary skill in the art, including equivalents and approximations due to the experimental and / or measurement conditions for such given value. For example, the term “about” in the context of a given value or range refers to a value or range that is within 20%, preferably within 15%, more preferably within 10%, more preferably within 9%, more preferably within 8%, more preferably within 7%, more preferably within 6%, and more preferably within 5% of the given value or range.

[0062] The expression “and / or” where used herein is to be taken as specific disclosure of each of the specified features or components with or without the other. For example, “A and / or B” is to be taken as specific disclosure of each of (i) A, (ii) B, and (iii) A and B, just as if each is set out individually herein. Unless specifically stated or obvious from context, as used herein the term “or” is understood to be inclusive and covers both “or” and “and”. For example, an embodiment of “a composition comprising A or B” would typically present an aspect with a composition comprising both A and B. “Or” should, however, be construed to exclude those aspects presented that cannot be combined without contradiction (e.g., a composition pH that is between 9 and 10 or between 7 and 8).

[0063] It is to be understood herein that terms such as “from 1 to 20” include any individual values comprised within and including 1 and 20. Therefore, the term “from 1 to 20” includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and / or 20. Terms such as “from 1 to 20” also include any individual sub-ranges comprised within and including from 1 to 20. The term “from 1 to 20” therefore also includes sub-ranges such as “from 1 to 9”, “from 2 to 9”, “from 3 to 5”, from 5 to 9”, “from 5 to 20”, “from 8 to 20” etc. The same applies for similar expressions such as and not limited to “from 1 to 19”, “from 1 to 18”, “from 1 to 10”, “from 1 to 9”, “from 5 to 15”, etc.

[0064] It is to be understood herein that terms such as “from about 15 to about 35” include any individual values comprised within and including 15 and 35. Therefore, terms such as “from about 15 to about 35” include any number between and including 15 and 35 such as 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 and / or 35. Terms such as “from about 15 to about 35” also include any individual sub-ranges comprised within and Attorney Docket No.35PH-005 / 03WO 349552-2048 including from 15 to 35, “from about 16 to about 34”, “from about 16 to about 24”, from about 24 to about 34” and the like. The term “about” in the context of the number of amino acids means that the specified number of amino acids is specifically encompassed and allows a ZGVOGXOTS TL &)- 2 in the number of amino acid residues. As such, the terms such as “from about 15 to about 35” also includes “from 13 to 37”, “from 13 to 35”, “from 17 to 37”, from 17 to 35”, etc. The same applies for similar expressions such as and not limited to “from about 16 to about 34”, “from about 16 to about 24”, from about 24 to about 34” and the like.

[0065] It is to be understood herein that terms such as “at least 80% identical” include any individual values comprised within and including from 80% to 100% and including 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% and 100%. The term “at least 80% identical” also includes any individual sub-ranges comprised within and including from 80% to 100%, such as for example, “from 85% to 99%”, “from 97% to 100%”, “from 90% to 100%”, etc. The same applies for similar expressions such as, and not limited to, expressions such as “at least 70% identical”, “at least 90% identical”, and the like.

[0066] As used herein, the term “IC50” refers to the half maximal inhibitory concentration (i.e., the concentration of a substance that is required for 50% inhibition in vitro). It is a measure of the potency or effectiveness of a substance in inhibiting a specific biological or biochemical function. IC50 values are typically expressed as molar concentration. The IC50 of an inhibitor can be determined by constructing a dose-response curve and examining the effect of different concentrations of inhibitor on the specific biological or biochemical function in question.

[0067] As used herein, the term “inhibition potency” refers to effectiveness of a substance in inhibiting a specific biological or biochemical function such as, without limitation, binding between a protein receptor and its ligand, or activation of a cell receptor by its ligand. In some embodiments, potency of inhibition is determined by measuring the IC50 of an inhibitor for a particular ligand or substrate. In that case, relative inhibition potency for different inhibitors and / or ligands may be assessed by comparing IC50 values. For example, a relative inhibition potency of 3:1 means the ratio of IC50 values for two substances being compared is 3:1, wherein the first substance has a lower inhibition potency (i.e., a greater IC50) than the second substance. A relative inhibition potency of 1:3 means the ratio of IC50 values for two substances being compared is 1:3, wherein the first substance has a greater inhibition potency (i.e., a lower IC50) than the second substance. As the IC50 of an inhibitor can vary depending on the assay conditions, relative inhibition potency for different inhibitors and / or ligands is Attorney Docket No.35PH-005 / 03WO 349552-2048 generally determined by comparing IC50 values obtained under the same assay conditions. The terms “inhibition potency”, “inhibitory potency”, “potency of inhibition” and “neutralization potency” are used interchangeably herein.

[0068] As used herein, the term “substantially the same” in reference to relative inhibition potency means that two proteins have a relative inhibition potency that is about the same, e.g., no more than about 2-fold different $&)- 2-fold) under the same experimental conditions, e.g., the ratio of IC50 values for the two proteins is about 2:1, 1:2, or 1:1.

[0069] As used herein, the term “functionally equivalent” refers to variant sequences that have the same or substantially the same biological activity or function as the original sequence from which it is derived, e.g., no significant change in physiological, chemical, physiochemical or functional properties compared to the original sequence. The term “substantially identical” refers to sequences that are functionally equivalent to the original or reference sequence and have a high degree of sequence identity thereto. Generally, a substantially identical sequence is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% identical to the original or reference sequence and has the same function. In some cases when referring to nucleic acid sequences, a substantially identical sequence hybridizes to the original sequence under high stringency conditions, for example at salt and temperature conditions substantially equivalent to 0.5 X SSC to about 5 X SSC and 65oC for both hybridization and wash.

[0070] The term “dimeric” refers to the presence of two polypeptides as described herein in a TGFa superfamily ligand binding agent (also referred to herein as a “binding agent”). “Homodimeric” means the two polypeptides have the same amino acid sequence, whereas “heterodimeric” means the two polypeptides have different amino acid sequences.

[0071] The term “divalent” refers to the presence of two TGFaR superfamily ligand binding regions (e.g., the ectodomains) in a TGFa superfamily ligand binding agent.

[0072] As used herein, a "recombinant polypeptide" is a polypeptide made through the use of recombinant DNA technology or genetic engineering. In the context of the present disclosure, recombinant polypeptides are often referred to as “polypeptide constructs” or simply as “polypeptides”.

[0073] Proteins (including fragments thereof, preferably biologically active fragments, and peptides, usually having less than 30 amino acids) comprise two or more amino acids coupled to each other via a covalent peptide bond (resulting in a chain of amino acids). The term Attorney Docket No.35PH-005 / 03WO 349552-2048 "polypeptide" as used herein describes a group of molecules, which usually consist of more than 10 amino acids. The terms “polypeptide”, “polypeptide chain” and “chain” are used interchangeably herein. Polypeptides may further form multimers such as dimers, trimers, and higher oligomers, i.e., consisting of more than one polypeptide molecule. Polypeptide molecules forming such dimers, trimers etc. may be identical or non-identical. The corresponding higher order structures of such multimers are, consequently, termed homo- or heterodimers, homo- or heterotrimers etc. An example for a heteromultimer is an antibody molecule, which, in its naturally occurring form, consists of two identical light polypeptide chains and two identical heavy polypeptide chains. The terms "peptide", "polypeptide" and "protein" also refer to naturally modified peptides / polypeptides / proteins wherein the modification is effected, e.g. by post-translational modifications like glycosylation, acetylation, phosphorylation and the like. A "peptide", "polypeptide" or "protein" when referred to herein may also be chemically modified such as pegylated. Such modifications are well known in the art and described herein.

[0074] As used herein, the terms "(specifically) binds to", (specifically) recognizes", “specific for”, "is (specifically) directed to", and "(specifically) reacts with" mean that a polypeptide interacts or specifically interacts with a given target(s), such as a specific member(s) of the TGFf superfamily of ligands. Specific binding is believed to be effected by specific motifs in the amino acid sequence of a polypeptide. Thus, binding is achieved as a result of their primary, secondary and / or tertiary structure as well as the result of secondary modifications of said structures. The specific interaction of the target-interaction-site with its specific target may result in a simple binding of said site to the target. Moreover, the specific interaction of the target-interaction-site with its specific target may alternatively or additionally result in the initiation of a signal, e.g. due to the induction of a change of the conformation of the target, an oligomerization of the target, etc., or may block the target from performing another activity, such as binding to an endogenous receptor.

[0075] Generally, binding is considered specific when the binding affinity is about 10-12 to 10-9 M, 10-12 to 10-19 M, 10-11 to 10-9 M, or of about 10-11 to 10-9 M. Whether a polypeptide or binding agent specifically reacts with or binds to a target can be tested readily by, inter alia, comparing the reaction of the polypeptide or binding agent with a target with the reaction of the polypeptide or binding agent with other proteins. In some embodiments, a polypeptide or binding agent of the disclosure does not substantially bind to TGFf superfamily ligands other than the desired ligands, e.g., does not substantially bind to BMP-9. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0076] As used herein, the term "does not substantially bind" or "is not capable of binding" means that a polypeptide or binding agent of the present disclosure does not demonstrate detectable binding to a given target, e.g., does not show reactivity of more than 30%, not more than 20%, not more than 10%, or not more than 9%, 8%, 7%, 6%, 5% or 3% with the given target.

[0077] As used herein, the term “selectively binds” is used to mean that a polypeptide binds to a target site that is not shared with other proteins. In general, a selective binding agent will not cross-react with other proteins and exclusively binds to the designated target protein(s). In the context of the present disclosure, “selective for activin A and GDF-8” means that a polypeptide or binding agent binds or neutralizes the activin A and GDF-8 ligands exclusively, without substantially binding or neutralizing other TGFf superfamily ligands such as, e.g., BMP-9.

[0078] “Half-life” means the time where 50% of an administered drug is eliminated through biological processes, e.g., metabolism, excretion, etc.

[0079] “Hepatic first-pass metabolism” refers to the propensity of a drug to be metabolized upon first contact with the liver, i.e., during its first pass through the liver.

[0080] “Volume of distribution” refers to the degree of retention of a drug throughout the various compartments of the body, such as, e.g., intracellular and extracellular spaces, tissues and organs, etc. and the distribution of the drug within these compartments.

[0081] “Degree of blood serum binding” refers to the propensity of a drug to interact with and bind to blood serum proteins, such as albumin, leading to a reduction or loss of biological activity of the drug.

[0082] The term "amino acid" or "amino acid residue" typically refers to an amino acid having its art recognized definition such as an amino acid selected from the group consisting of: alanine (Ala or A); arginine (Arg or R); asparagine (Asn or N); aspartic acid (Asp or D); cysteine (Cys or C); glutamine (Gln or Q); glutamic acid (Glu or E); glycine (Gly or G); histidine (His or H); isoleucine (He or I): leucine (Leu or L); lysine (Lys or K); methionine (Met or M); phenylalanine (Phe or F); pro line (Pro or P); serine (Ser or S); threonine (Thr or T); tryptophan (Trp or W); tyrosine (Tyr or Y); and valine (Val or V), although modified, synthetic, or rare amino acids may be used as desired. Generally, amino acids can be grouped as having a nonpolar side chain (e.g., Ala, Cys, He, Leu, Met, Phe, Pro, Val); a negatively Attorney Docket No.35PH-005 / 03WO 349552-2048 charged side chain (e.g., Asp, Glu); a positively charged sidechain (e.g., Arg, His, Lys); or an uncharged polar side chain (e.g., Asn, Cys, Gin, Gly, His, Met, Phe, Ser, Thr, Trp, and Tyr).

[0083] "Percent (%) nucleic acid sequence identity" with respect to the nucleic acid sequence of the polypeptides or binding agents identified herein is defined as the percentage of nucleotide residues in a candidate sequence that are identical with the nucleotide residues in the coding sequence of the polypeptides or binding agents. A specific method utilizes the BLASTN module of WU-BLAST-2 set to the default parameters, with overlap span and overlap fraction set to 1 and 0.125, respectively. $#"% superfamily ligand binding agents

[0084] In some embodiments, the present disclosure provides combinations comprising a TGFa WYUKVLGROQ] ligand binding agent and a GLP-1 agonist, wherein the binding agent comprises an ActRIIB-ECD region, a linker region, and an Fc domain (also referred to herein as “binding agents” or “TGFa QOMGSJ HOSJOSM GMKSXW_). The individual components of the binding agents described herein are described in further detail in the following sections. In general, however, the binding agents described herein are dimeric proteins comprising two polypeptides each comprising an ActRIIB-ECD, a peptide linker, and an Fc domain monomer. The two polypeptides assemble via the Fc domain monomers to form the dimeric binding agents described herein. See schematic in Fig.8. When assembled, the Fc domain monomers in each of the polypeptides form a dimeric Fc domain at one terminus and a divalent ActRIIB- ECD region at the other terminus. Binding agents of the present disclosure can bind to one or more ligand selected from activin A, activin B, GDF-8, and GDF-11 and inhibit signaling of the one or more ligand through their respective receptors, without substantially binding to BMP-9 and / or BMP-10, and / or inhibiting BMP-9 and / or BMP-10 signaling through its receptor. Binding agents may also have further biological activities or functions such as binding to other ligands or targets and the like, as further described herein.

[0085] In some embodiments, the binding agents of the present disclosure include two polypeptide chains that are associated via an Fc domain monomer of an antibody or via a constant CH2 domain, a constant CH3 domain and / or via a combination of CH2 and CH3. The constant region of the antibody may be from a human IgG1, IgG2, IgG3 or IgG4 antibody, or substantially identical thereto. The association of both polypeptide chains generally occurs during expression and secretion of the protein, e.g. in mammalian cells. The Fc domain monomer generally comprises a CH2, a CH3, or a CH2 and a CH3 from an antibody heavy Attorney Docket No.35PH-005 / 03WO 349552-2048 chain that is of human origin and typically provides for disulfide crosslinking between single chain polypeptides. In an embodiment, the Fc domain monomer provides for at least one disulfide link between single chain polypeptides. In another embodiment, the Fc domain monomer provides for at least two disulfide links between single chain polypeptides. In some cases, the antibody heavy chain also provides for Protein A-based isolation of the dimeric polypeptide, e.g. after production in host cells.

[0086] Certain E<;a superfamily ligand binding agents and point mutations in the ECD are described in the art. See e.g., WO 2021 / 158675; WO 2022 / 150590; WO 2021 / 158675; WO 2022 / 072882; WO 2021 / 189019; and WO 2021 / 189010. Although point mutations in the ActRIIB ECD have been described in the context of other E<;a WYUKVLGROQ] QOMGSJ binding agents, the effects of these mutations in the context of these previously described agents do not predict the effects of these same mutations in the context of the binding agents described herein. See e.g., PCT / CA2023 / 050116 describing the unpredictability of point mutations in the ActRIIB ECD when combined with linkers of varying lengths. As such, the efficacy of a particular binding agent described herein is determined not only by the mutations comprised in the extracellular ligand binding domain, but also by the length of the linker used.

[0087] In some embodiments, binding agents of the present disclosure comprise homodimers, i.e., dimers of a polypeptide having the sequence set forth in any one of SEQ ID NOs: 174- 251, or a sequence at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof. In other embodiments, binding agents comprise heterodimers, i.e., dimers of two different polypeptides, at least one of the polypeptides having the sequence set forth in any one of SEQ ID NOs: 174-251, or a sequence at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof.

[0088] In some embodiments, the binding agents of the present disclosure comprise a dimer of a polypeptide comprising an ActRIIB-ECD comprising an L33W mutation and a long peptide linker. In some embodiments, the peptide linker is, or is at least, 10 amino acids in length. In some embodiments, the peptide linker is, or is at least, 14 amino acids in length. In some embodiments, the peptide linker is, or is at least, 19 amino acids in length. In some embodiments, the peptide linker is, or is at least, 39 amino acids in length. In some embodiments, the binding agents of the present disclosure comprise a dimer of a polypeptide comprising or consisting of an amino acid sequence selected from SEQ ID NOs: 211 and 230- Attorney Docket No.35PH-005 / 03WO 349552-2048 234, or a sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof.

[0089] In some embodiments, the binding agents of the present disclosure comprise a dimer of a polypeptide comprising or consisting of SEQ ID NO: 211, or a sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof. In some embodiments, the binding agents of the present disclosure comprise a dimer of a polypeptide comprising or consisting of SEQ ID NO: 230, or a sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof. In some embodiments, the binding agents of the present disclosure comprise a dimer of a polypeptide comprising or consisting of SEQ ID NO: 231, or a sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof. In some embodiments, the binding agents of the present disclosure comprise a dimer of a polypeptide comprising or consisting of SEQ ID NO: 232, or a sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof. In some embodiments, the binding agents of the present disclosure comprise a dimer of a polypeptide comprising or consisting of SEQ ID NO: 233, or a sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof. In some embodiments, the binding agents of the present disclosure comprise a dimer of a polypeptide comprising or consisting of SEQ ID NO: 234, or a sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto, or a functionally equivalent variant thereof. Activin receptor type IIB ectodomain variants

[0090] As used herein, the term “Activin receptor type IIB ectodomain variants” or “ActRIIB- ECD variants” refers to a polypeptide comprising the soluble, extracellular portion of the single transmembrane receptor, ActRIIB, that has at least one amino acid substitution relative to a wild type extracellular ActRIIB. The sequence of the wild type human ActRIIB-ECD is shown in SEQ ID NO: 2 (Table 1). Unless otherwise noted, indicated positions for amino acid substitutions are numbered according to the amino acid sequence of SEQ ID NO: 2. For the purposes of this disclosure, the “human wild type ActRIIB-ECD” refers to SEQ ID NO: 2. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0091] In some embodiments, the ActRIIB-ECD variant comprises one or more amino acid substitutions at a position selected from L14, G27, L33, L55, and T69. In some embodiments, the ActRIIB-ECD variant polypeptide comprises one or more amino acid substitutions selected from L14E, L14H, L14S, L14N, L14Q, L14D, G27E, G27D, G27N, G27Q, G27K, G27T, G27M, L33R, L33Y, L33F, L33Q, L33W, L33E, L33K, L33M, L55Y, L55Q, L55M, L55I, L69H, L69Q, L69E, L69R, L69Y, and L69W. In some embodiments, the ActRIIB-ECD variant comprises one or more amino acid substitutions selected from L33R, L33Y, L33F, L33Q, L33W, L33E, L33K, and L33M. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution of L33Y. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution of L33W. Other amino acid substitutions in the ActRIIB- ECD are known in the art (e.g., WO 2021 / 158675; WO 2022 / 150590; WO 2021 / 158675; WO 2022 / 072882; WO 2021 / 189019; and WO 2021 / 189010, each of which are incorporated herein by reference). These additional mutations can be used in combination with the linkers described herein, and incorporated into the binding agents described herein, to alter ligand binding properties of the ActRIIB-ECD.

[0092] In some embodiments, the ActRIIB-ECD variant comprises the amino acid sequence set forth in any one of SEQ ID NOs: 4-62. In some embodiments, an ActRIIB-ECD variant comprises at least 85% (e.g., at least 85%, at least 87%, at least 90%, at least 92%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or greater) amino acid sequence identity to the sequence of a wild type human ActRIIB-ECD. In some embodiments, an ActRIIB-ECD variant may have at least 85% (e.g., at least 85%, at least 87%, at least 90%, at least 92%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or greater) amino acid sequence identity to the sequence set forth in SEQ ID NO: 2.

[0093] In some embodiments, the amino acid sequence of the ActRIIB-ECD variant comprises at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to any one of SEQ ID NOs: 4-62.

[0094] In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27 and comprises an amino acid sequence that is at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to any one of SEQ ID NOs: 4-9. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27 and comprises or consists of an amino acid sequence selected from SEQ ID NOs: 4-9. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27E and comprises or consists of the amino acid sequence of SEQ ID NO: 4. In some Attorney Docket No.35PH-005 / 03WO 349552-2048 embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27N and comprises or consists of the amino acid sequence of SEQ ID NO: 5. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27Q and comprises or consists of the amino acid sequence of SEQ ID NO: 6. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27K and comprises or consists of the amino acid sequence of SEQ ID NO: 7. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27T and comprises or consists of the amino acid sequence of SEQ ID NO: 8. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27M and comprises or consists of the amino acid sequence of SEQ ID NO: 9.

[0095] In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33 and comprises an amino acid sequence that is at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to any one of SEQ ID NOs: 10-18. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33 and comprises or consists of an amino acid sequence selected from SEQ ID NOs: 10-18. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33F and comprises or consists of the amino acid sequence of SEQ ID NO: 10. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Q and comprises or consists of the amino acid sequence of SEQ ID NO: 11. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 12. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 13. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33H and comprises or consists of the amino acid sequence of SEQ ID NO: 14. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33R and comprises or consists of the amino acid sequence of SEQ ID NO: 15. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33E and comprises or consists of the amino acid sequence of SEQ ID NO: 16. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33K and comprises or consists of the amino acid sequence of SEQ ID NO: 17. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33M and comprises or consists of the amino acid sequence of SEQ ID NO: 18. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0096] In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position T69 and comprises an amino acid sequence that is at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NOs: 19-24. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27 and comprises or consists of SEQ ID NO: 19-24. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position T69H and comprises or consists of the amino acid sequence of SEQ ID NO: 19. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position T69Q and comprises or consists of the amino acid sequence of SEQ ID NO: 20. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position T69E and comprises or consists of the amino acid sequence of SEQ ID NO: 21. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position T69R and comprises or consists of the amino acid sequence of SEQ ID NO: 22. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position T69Y and comprises or consists of the amino acid sequence of SEQ ID NO: 23. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position T69W and comprises or consists of the amino acid sequence of SEQ ID NO: 24.

[0097] In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33 and at position T69 and comprises an amino acid sequence that is at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NOs: 25- 31. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33 and at position T69 and comprises or consists of SEQ ID NO: 25-31. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and T69R and comprises or consists of the amino acid sequence of SEQ ID NO: 25. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and T69Y and comprises or consists of the amino acid sequence of SEQ ID NO: 26. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and T69W and comprises or consists of the amino acid sequence of SEQ ID NO: 27. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and T69H and comprises or consists of the amino acid sequence of SEQ ID NO: 28. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and T69Q and comprises or consists of the amino acid sequence of SEQ ID NO: 29. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and T69E and comprises or consists of the amino acid sequence of SEQ ID NO: 30. In some Attorney Docket No.35PH-005 / 03WO 349552-2048 embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33F and T69Q and comprises or consists of the amino acid sequence of SEQ ID NO: 31.

[0098] In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27 and at position L33 and comprises an amino acid sequence that is at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NOs: 32- 48. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27 and at position L33 and comprises or consists of SEQ ID NO: 32-48. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27E and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 32. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27D and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 33. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27N and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 34. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27Q and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 35. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27K and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 36. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27T and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 37. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27M and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 38. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27D and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 39. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27E and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 40. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27N and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 41. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27Q and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 42. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27D and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 43. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27E and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 44. In Attorney Docket No.35PH-005 / 03WO 349552-2048 some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27N and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 45. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27Q and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 46. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27T and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 47. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position G27M and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 48.

[0099] In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14 and at position L33 and comprises an amino acid sequence that is at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NOs: 49- 58. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14 and at position L33 and comprises or consists of SEQ ID NO: 49-58. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14Q and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 49. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14D and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 50. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14N and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 51. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14E and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 52. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14H and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 53. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14S and L33Y and comprises or consists of the amino acid sequence of SEQ ID NO: 54. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14E and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 55. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14D and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 56. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14N and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 57. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L14Q and L33W and comprises or consists of the amino acid sequence of SEQ ID NO: 58. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0100] In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33 and at position L55 and comprises an amino acid sequence that is at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NOs: 59- 62. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33 and at position L55 and comprises or consists of SEQ ID NO: 59-62. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and L55Y and comprises or consists of the amino acid sequence of SEQ ID NO: 59. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and L55Q and comprises or consists of the amino acid sequence of SEQ ID NO: 60. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and L55M and comprises or consists of the amino acid sequence of SEQ ID NO: 61. In some embodiments, the ActRIIB-ECD variant comprises an amino acid substitution at position L33Y and L55I and comprises or consists of the amino acid sequence of SEQ ID NO: 62.

[0101] Exemplary ActRIIB ECDs are provided in Table 1. Amino acid substitutions are indicated by bold and enlarged text. Table 1: Exemplary ActRIIB and ActRIIB variant ECDs ECD AA Sequence SEQ ID wild type ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKK 2 ActRIIB-ECD GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT wild type ILGRSETQECLFFNANWEKDRTNQTGVEPCYGDKDKRRHCFATWKNISGSI 3 ActRIIA-ECD EIVKQGCWLDDINCYDRTDCVEKKDSPEVYFCCCEGNMCNEKFSYFPEMEV TQPTSNPVTPKPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEEEQDKRLHCYASWRNSSGTIELVKK4 G27E GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCENEQDKRLHCYASWRNSSGTIELVKK 5 G27N GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEQEQDKRLHCYASWRNSSGTIELVKK 6 G27Q GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEKEQDKRLHCYASWRNSSGTIELVKK7 G27K GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCETEQDKRLHCYASWRNSSGTIELVKK8 G27T GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEMEQDKRLHCYASWRNSSGTIELVKK 9 G27M GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT Attorney Docket No.35PH-005 / 03WO 349552-2048 ECD AA Sequence SEQ ID ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEGEQDKRFHCYASWRNSSGTIELVKK10 L33F GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEGEQDKRQHCYASWRNSSGTIELVKK11 L33Q GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 12 L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKK 13 L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEGEQDKRHHCYASWRNSSGTIELVKK14 L33H GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEGEQDKRRHCYASWRNSSGTIELVKK15 L33R GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKREHCYASWRNSSGTIELVKK 16 L33E GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRKHCYASWRNSSGTIELVKK 17 L33K GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEGEQDKRMHCYASWRNSSGTIELVKK18 L33M GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKK 19 T69H GCWLDDFNCYDRQECVAHEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKK 20 T69QGCWLDDFNCYDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKK 21 T69E GCWLDDFNCYDRQECVAEEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKK 22 T69R GCWLDDFNCYDRQECVAREENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKK 23 T69YGCWLDDFNCYDRQECVAYEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKK 24 T69W GCWLDDFNCYDRQECVAWEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 25 L33Y T69R GCWLDDFNCYDRQECVAREENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 26 L33Y T69Y GCWLDDFNCYDRQECVAYEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 27 L33Y T69WGCWLDDFNCYDRQECVAWEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPT Attorney Docket No.35PH-005 / 03WO 349552-2048 ECD AA Sequence SEQ ID ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK28 L33Y T69H GCWLDDFNCYDRQECVAHEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK29 L33Y T69Q GCWLDDFNCYDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 30 L33Y T69E GCWLDDFNCYDRQECVAEEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRFHCYASWRNSSGTIELVKK 31 L33F T69Q GCWLDDFNCYDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEEEQDKRYHCYASWRNSSGTIELVKK32 G27E L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEDEQDKRYHCYASWRNSSGTIELVKK 33 G27D L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCENEQDKRYHCYASWRNSSGTIELVKK 34 G27N L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEQEQDKRYHCYASWRNSSGTIELVKK 35 G27Q L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEKEQDKRYHCYASWRNSSGTIELVKK36 G27K L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCETEQDKRYHCYASWRNSSGTIELVKK 37 G27T L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEMEQDKRYHCYASWRNSSGTIELVKK 38 G27M L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEDEQDKRYHCYASWRNSSGTIELVKK 39 G27D L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEEEQDKRYHCYASWRNSSGTIELVKK 40 G27E L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCENEQDKRYHCYASWRNSSGTIELVKK 41 G27N L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEQEQDKRYHCYASWRNSSGTIELVKK 42 G27Q L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEDEQDKRWHCYASWRNSSGTIELVKK43 G27D L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEEEQDKRWHCYASWRNSSGTIELVKK 44 G27E L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCENEQDKRWHCYASWRNSSGTIELVKK 45 G27N L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT Attorney Docket No.35PH-005 / 03WO 349552-2048 ECD AA Sequence SEQ ID ActRIIB-ECDETRECIYYNANWELERTNQSGLERCEQEQDKRWHCYASWRNSSGTIELVKK46 G27Q L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPTGGGGSGGGGSGGGGSGGGG ActRIIB-ECDETRECIYYNANWELERTNQSGLERCETEQDKRWHCYASWRNSSGTIELVKK47 G27T L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEMEQDKRWHCYASWRNSSGTIELVKK 48 G27M L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWEQERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 49 L14Q L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWEDERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK50 L14D L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWENERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK51 L14N L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWEEERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 52 L14E L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWEHERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 53 L14H L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWESERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK54 L14S L33Y GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWEEERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKK55 L14E L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWEDERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKK 56 L14D L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWENERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKK 57 L14N L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECDETRECIYYNANWEQERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKK58 L14Q L33W GCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 59 L33Y L55Y GCWYDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 60 L33Y L55Q GCWQDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 61 L33Y L55M GCWMDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT ActRIIB-ECD ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKK 62 L33Y L55I GCWIDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTY EPPPT Attorney Docket No.35PH-005 / 03WO 349552-2048

[0102] In some embodiments, an ActRIIB-ECD variant of the disclosure further includes an extension of up to 5 amino acids at the N-terminus. In some embodiments, the ActRIIB-ECD variant of the disclosure further includes an extension of 5 amino acids at the N-terminus, e.g., of GRGEA (SEQ ID NO: 63). In some embodiments, the ActRIIB-ECD variant of the disclosure further includes an extension at the N-terminus of 4 amino acids, 3 amino acids, 2 amino acids, or 1 amino acid, for example and without limitation, RGEA, GEA, EA, or A. In some embodiments, an ActRIIB-ECD variant of the disclosure further includes an extension of 3 amino acids at the C-terminus. In some embodiments, the ActRIIB-ECD variant of the disclosure further includes an extension of 3 amino acids at the C-terminus, e.g., of APT.

[0103] Exemplary ActRIIB ECDs with N-terminal and C-terminal extensions are provided in Table 2. The extension amino acids are indicated in bold and italicized text. In some embodiments, any one of SEQ ID NOs: 4-62 can further comprise an N- or C-terminal extension. Table 2: ActRIIB-ECDs with N-terminal extensions ECD AA Sequence SEQ ID WT ActRIIB-:89 & GRGEAETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRN 65 N and C terminal SSGTIELVKKGCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNE RFTHLPEAGGPEVTYEPPPTAPT extensions WT ActRIIB-:89 & GRGEAETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRN 66 N terminal extension SSGTIELVKKGCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNE RFTHLPEAGGPEVTYEPPPT WT ActRIIB-:89 & ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTI 67 C terminal extension ELVKKGCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHL PEAGGPEVTYEPPPTAPT

[0104] ActRIIB-ECD variants of the disclosure have been designed to maximize therapeutic efficacy in certain disease indications while minimizing adverse effects, specifically to prevent or reduce disruption of endogenous BMP-9 and / or BMP-10 signaling, while maintaining GSJ)TV OSIVKGWOSM SKYXVGQO^GXOTS UTXKSI] LTV TXNKV E<;a WYUKVLGROQ] QOMGSJW WYIN GW GIXOZOS 6' activin B, GDF-8, and / or GDF-11. ActRIIB-ECD variants of the disclosure exhibit: (1) similar or improved binding to activin A, activin B, GDF-8, and / or GDF-11 compared to wild type ActRIIB-ECD, which allows them to compete with endogenous receptors for ligand binding and reduce or inhibit endogenous receptor signaling; and (2) reduced binding to BMP-9 compared to wild type ActRIIB-ECD, which avoids toxicity associated with inhibition of BMP-9 signaling; and optionally (3) similar or reduced binding to or inhibition of BMP-10, which avoids toxicity associated with inhibition of BMP-10 signaling. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0105] In some embodiments, ActRIIB-ECD variants of the disclosure bind to one or more ligand selected from activin A, activin B, GDF-8, and GDF-11 and inhibit signaling of the one or more ligand through their respective receptors, without substantially binding to BMP-9 or BMP-10 and / or inhibiting BMP-9 or BMP-10 signaling through their receptor(s).

[0106] In some embodiments, the inhibition potency of an ActRIIB-ECD variant of the disclosure for human BMP-9 signaling is reduced by about 5-fold compared to the inhibition potency of the human wild type ActRIIB-ECD for human BMP-9 signaling.

[0107] In some embodiments, the inhibition potency of an ActRIIB-ECD variant of the disclosure for human BMP-9 signaling is reduced by about 10-fold compared to the inhibition potency of the human wild type ActRIIB-ECD for human BMP-9 signaling.

[0108] In some embodiments, the inhibition potency of an ActRIIB-ECD variant of the disclosure for human BMP-9 signaling is reduced by about 100-fold compared to the inhibition potency of the human wild type ActRIIB-ECD for human BMP-9 signaling.

[0109] In some embodiments, the inhibition potency of an ActRIIB-ECD variant of the disclosure for human BMP-10 signaling is reduced by about 5-fold compared to the inhibition potency of the human wild type ActRIIB-ECD for human BMP-10 signaling.

[0110] In some embodiments, the inhibition potency of an ActRIIB-ECD variant of the disclosure for human BMP-10 signaling is reduced by about 10-fold compared to the inhibition potency of the human wild type ActRIIB-ECD for human BMP-10 signaling.

[0111] In some embodiments, the inhibition potency of an ActRIIB-ECD variant of the disclosure for human BMP-10 signaling is reduced by about 100-fold compared to the inhibition potency of the human wild type ActRIIB-ECD for human BMP-10 signaling.

[0112] In some embodiments, the inhibition potency of ActRIIB-ECD variant of the disclosure for the one or more ligand selected from activin A, activin B, GDF-8, and GDF-11 is increased or is substantially the same as the inhibition potency of the human wild type ActRIIB-ECD for the same one or more ligand.

[0113] In some embodiments, the ActRIIB-ECD variant of the disclosure has greater inhibition potency for activin A and lower inhibition potency for BMP-9 and / or BMP-10 compared to the human wild type ActRIIB-ECD. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0114] In some embodiments, the ActRIIB-ECD variant of the disclosure has greater inhibition potency for activin B and lower inhibition potency for BMP-9 and / or BMP-10 compared to the human wild type ActRIIB-ECD.

[0115] In some embodiments, the ActRIIB-ECD variant of the disclosure has greater inhibition potency for both activin A and activin B and lower inhibition potency for BMP-9 and / or BMP-10 compared to the human wild type ActRIIB-ECD.

[0116] In some embodiments, the ActRIIB-ECD variant of the disclosure has greater inhibition potency for GDF-8 and lower inhibition potency for BMP-9 and / or BMP-10 compared to the human wild type ActRIIB-ECD.

[0117] In some embodiments, the ActRIIB-ECD variant of the disclosure has greater inhibition potency for GDF-11 and lower inhibition potency for BMP-9 and / or BMP-10 compared to the human wild type ActRIIB-ECD.

[0118] In some embodiments, the ActRIIB-ECD variant of the disclosure has reduced inhibition potency for BMP-10 compared to the human wild type ActRIIB-ECD.

[0119] In some embodiments, the ActRIIB-ECD variant of the disclosure has greater inhibition potency for both activin A and / or activin B; lower inhibition potency for BMP-9; and lower inhibition potency for BMP-10 compared to the human wild type ActRIIB-ECD.

[0120] In some embodiments, the ActRIIB-ECD variant of the disclosure does not cause a vascular complication in a subject. In some embodiments, the ActRIIB-ECD variant of the disclosure does not increase vascular permeability or leakage in a subject.

[0121] Consequently, in accordance with the disclosure there are provided herein novel polypeptides comprising an Activin receptor type IIB (ActRIIB) ectodomain (ECD) variant, the variant having one or more amino acid substitution relative to the sequence of the human wild type ActRIIB-ECD, having a tailored TGFa superfamily ligand specificity in order to maximize therapeutic efficacy while minimizing adverse effects, specifically with the goal of preventing or reducing disruption of endogenous BMP-9 and / or BMP-10 signaling, while RGOSXGOSOSM GSJ)TV OSIVKGWOSM SKYXVGQO^GXOTS UTXKSI] LTV TXNKV E<;a WYUKVLGROQ] QOMGSJW WYIN as activin A, activin B, GDF-8, and / or GDF-11. Polypeptides comprising ActRIIB ECD variants

[0122] In some embodiments, the present disclosure provides polypeptides comprising an ActRIIB ECD variant fused, via a linker, to an Fc domain monomer. In some embodiments, Attorney Docket No.35PH-005 / 03WO 349552-2048 the polypeptides comprise, from N-terminus to C-terminus, an ActRIIB ECD variant – peptide linker – Fc domain monomer. The polypeptides comprising ActRIIB ECDs can dimerize via cysteine bonds between Fc domain monomers to form the E<;a WYUKVLGROQ] QOMGSJ binding agents described herein. Linkers

[0123] In some embodiments, the ActRIIB ECD variants described herein are fused to a heterologous domain by way of a linker. In some embodiments, the heterologous domain increases stability of the polypeptide. In some embodiments, the heterologous domain is selected from the group consisting of an Fc domain monomer (e.g., a wild-type Fc domain monomer, an Fc domain monomer with one or more amino acid substitutions), an albumin- binding peptide, a fibronectin domain, or a human serum albumin domain.

[0124] As used herein, the terms “peptide linker” and “linker” are used interchangeably to refer to a short stretch of amino acids used to connect two functional domains together in a polypeptide chain. For example, in some embodiments of the polypeptides or binding agents of the disclosure, the ActRIIB-ECD variant and the Fc domain monomer are linked together on a polypeptide chain via one or more peptide linkers. Peptide linkers can also be used to attach other domains or modules or regions (such as half-life extending domains) to the polypeptides or binding agents of the disclosure. The term “long linker” as used herein refers to a linker that is at least 10 amino acids in length (i.e., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more amino acids in length). The term “short linker” as used herein refers to a linker that is less than 10 amino acids in length (i.e., 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acids in length)

[0125] Suitable peptide linkers are known in the art, and include, for example, peptide linkers containing flexible amino acid residues such as glycine, alanine, and serine. In some embodiments, a linker can contain motifs, e.g., multiple or repeating motifs, of GA, GS, GG, GGA, GGS, GGG, GGGA (SEQ ID NO: 126), GGGS (SEQ ID NO: 125), GGGG (SEQ ID NO: 104), GGGGA (SEQ ID NO: 124), GGGGS (SEQ ID NO: 103), GGGGG (SEQ ID NO: 123), GGAG (SEQ ID NO: 122), GGSG (SEQ ID NO: 121), AGGG (SEQ ID NO: 120), or SGGG (SEQ ID NO: 110).

[0126] In some embodiments, a linker can contain 2 to 12 amino acids including motifs of GA or GS, e.g., GA, GS, GAGA (SEQ ID NO: 137), GSGS (SEQ ID NO: 129), GAGAGA (SEQ ID NO: 130), GSGSGS (SEQ ID NO: 131), GAGAGAGA (SEQ ID NO: 132), GSGSGSGS (SEQ ID NO: 133), GAGAGAGAGA (SEQ ID NO: 134), GSGSGSGSGS (SEQ Attorney Docket No.35PH-005 / 03WO 349552-2048 ID NO: 135), GAGAGAGAGAGA (SEQ ID NO: 136), and GSGSGSGSGSGS (SEQ ID NO: 138). In some embodiments, a linker can contain 3 to 12 amino acids including motifs of GGA or GGS, e.g., GGA, GGS, GGAGGA (SEQ ID NO: 139), GGSGGS (SEQ ID NO: 140), GGAGGAGGA (SEQ ID NO: 141), GGSGGSGGS (SEQ ID NO: 142), GGAGGAGGAGGA (SEQ ID NO: 143), and GGSGGSGGSGGS (SEQ ID NO: 144). In some embodiments, a linker can contain 4 to 12 amino acids including motifs of GGAG (SEQ ID NO: 145), GGSG (SEQ ID NO: 146), GGAGGGAG (SEQ ID NO: 147), GGSGGGSG (SEQ ID NO: 148), GGAGGGAGGGAG (SEQ ID NO: 149), and GGSGGGSGGGSG (SEQ ID NO: 150). In some embodiments, a linker can contain motifs of GGGGA (SEQ ID NO: 124) or GGGGS (SEQ ID NO: 103), e.g, GGGGAGGGGAGGGGA (SEQ ID NO: 151) and GGGGSGGGGSGGGGS (SEQ ID NO: 93). In some embodiments, an amino acid linker between an ActRIIB-ECD variant and a heterologous domain (e.g., an Fc domain monomer (e.g., a wild-type Fc domain monomer, an Fc domain monomer with one or more amino acid substitutions), an albumin-binding peptide, a fibronectin domain, or a human serum albumin domain) may be GGG, GGGA (SEQ ID NO: 126), GGGG (SEQ ID NO: 104), GGGAG (SEQ ID NO: 168), GGGAGG (SEQ ID NO: 169), or GGGAGGG (SEQ ID NO: 170).

[0127] In the event that a linker is used, the linker is generally of a length and sequence sufficient to ensure that each of the domains can, independently from one another, retain their differential binding specificities and / or functions. In some embodiments, peptide linkers which furthermore do not promote any secondary structures are selected. The linkage of said domains to each other can be provided, e.g., by genetic engineering, as described herein. Methods for preparing fused and operatively linked polypeptide constructs and expressing them in mammalian cells or bacteria are well-known in the art (e.g., WO 99 / 54440 or Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 2001).

[0128] In some embodiments, the linker comprises various permutations of amino acid sequences containing Gly and Ser. In some embodiments, the linkers are glycine and serine rich linkers. In some embodiments, the linker may be rich in glycine (e.g, 2-10, 2-5, 2-4, 2-3 glycine residues) or glycine and proline residues and may, for example, contain a single sequence of threonine / serine and glycines or repeating sequences of threonine / serine and / or glycines, e.g., GGG, GGGG (SEQ ID NO: 104), GGGS (SEQ ID NO: 125), TGGGG (SEQ ID NO: 108), SGGGG (SEQ ID NO: 109), TGGG (SEQ ID NO: 107), or SGGG (SEQ ID NO: Attorney Docket No.35PH-005 / 03WO 349552-2048 110) singlets, or repeats. Other near neutral amino acids, such as, but not limited to, Thr, Asn, Pro and Ala, may also be used in the linker sequence.

[0129] In some embodiments, the linker is 10 amino acids in length. In some embodiments, the linker is greater than 10 amino acids in length. In some embodiments, the linker has a length of at least 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 amino acids. In some embodiments, the linker is less than 40, 35, 30, 25, 22 or 20 amino acids. In some embodiments, the linker is 10-50, 10-40, 10-30, 10-25, 10-21, 10-15, 10-14, 12-14, 15-25, 17-22, 20, or 21 amino acids in length. In some embodiments, the linker is 14-40, 14-39, 14-35, 14-30, 14-25, or 14-20 amino acids in length. In some embodiments, the linker is at least 10 amino acids in length. In some embodiments, the linker is at least 14 amino acids in length. In some embodiments, the linker is at least 19 amino acids in length. In some embodiments, the linker is at least 39 amino acids in length. In some embodiments, the linker is 14 amino acids in length. In some embodiments, the linker is 19 amino acids in length. In some embodiments, the linker is 39 amino acids in length. In some embodiments, the linker is 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 amino acids in length. In further embodiments, the linkers have a length of at least 12, 14, 15, 20, 21, 25, 30, 35, 40, 45 or 50 amino acids.

[0130] In other embodiments, the linker is less than 10 amino acids in length. In some embodiments, the linker is 3 amino acids in length. In some embodiments, the linker is 6 amino acids in length. In some embodiments, the linker is 9 amino acids in length.

[0131] In some embodiments, the linker comprises SEQ ID NO: 98. In some embodiments, the linker comprises SEQ ID NO: 94. In some embodiments, the linker comprises SEQ ID NO: 89.

[0132] In some embodiments, the linker consists of SEQ ID NO: 98. In some embodiments, the linker consists of SEQ ID NO: 94. In some embodiments, the linker consists of SEQ ID NO: 89.

[0133] In some embodiments, the linker comprises or consists of the sequence set forth in any one of SEQ ID NOs: 68-170.

[0134] In some embodiments, linkers are Glycine-rich, often Glycine / Serine-rich, peptides of up to 40 amino acids, or from 1 to 40 amino acids, from 2 to 39 amino acids, from 3 to 39 amino acids, from 3 to 14 amino acids, from 3 to 19 amino acids, from 5 to 25 amino acids, Attorney Docket No.35PH-005 / 03WO 349552-2048 from 5 to 20 amino acids, from 5 to 15 amino acids, or from 15 to 25 amino acids. In some embodiments, peptide linkers comprise only a relatively small number of amino acid residues, e.g., 39 amino acids or less, 19 amino acids or less, 14 amino acids or less, 5 amino acids or less, or 3 amino acids of less. In certain embodiments, Gly-rich linkers are used. In one embodiment, a peptide linker may consist of the single amino acid Glycine (Gly). In another embodiment, a peptide linker comprises or consists of the amino acid sequence Gly-Gly-Gly- Gly-Ser, i.e. Gly4Ser, or polymers thereof, i.e. (Gly4Ser)n, where n is an integer of 1 or greater, or n is from 1 to 8 (e.g.1, 2, 3, 4, 5, 6, 7, or 8).

[0135] In some embodiments, the linker comprises the amino acid sequence GlyGlyGlyGlySer (GGGGS) (SEQ ID NO: 103), or repetitions thereof (GGGGS)n, where n > 2. In particular embodiments n > 3, or n = 3-10. In some embodiments, n > 4, or n = 4-10. In some embodiments, n is not greater than 4 in a (GGGGS)n linker. In some embodiments, n = 4-10, 4-9, 4-8, 4-7, 4-6, 4-5, 5-8, 5-7, or 5-6. In some embodiments, n = 3, 4, 5, 6, or 7. In some embodiments, n = 4. In some embodiments, a linker comprising a (GGGGS)n sequence also comprises an N-terminal threonine.

[0136] In some embodiments, a linker can also contain amino acids other than glycine, alanine, and serine, e.g., AAAL (SEQ ID NO: 152), AAAK (SEQ ID NO: 153), AAAR (SEQ ID NO: 154), EGKSSGSGSESKST (SEQ ID NO: 155), GSAGSAAGSGEF (SEQ ID NO: 156), AEAAAKEAAAKA (SEQ ID NO: 157), KESGSVSSEQLAQFRSLD (SEQ ID NO: 158), GENLYFQSGG (SEQ ID NO: 159), SACYCELS (SEQ ID NO: 160), RSIAT (SEQ ID NO: 161), RPACKIPNDLKQKVMNH (SEQ ID NO: 162), GGSAGGSGSGSSGGSSGASGTGTAGGTGSGSGTGSG (SEQ ID NO: 163), AAANSSIDLISVPVDSR (SEQ ID NO: 164), or GGSGGGSEGGGSEGGGSEGGGSEGGGSEGGGSGGGS (SEQ ID NO: 165). In some embodiments, a linker can contain motifs, e.g., multiple or repeating motifs, of EAAAK (SEQ ID NO: 166). In some embodiments, a linker can contain motifs, e.g., multiple or repeating motifs, of praline-rich sequences such as (XP)n, in which X may be any amino acid (e.g., A, K, or E) and n is from 1-5, and PAPAP (SEQ ID NO: 167).

[0137] The length of the peptide linker and the amino acids used can be adjusted depending on the two proteins involved and the degree of flexibility desired in the final protein fusion polypeptide. The length of the linker can be adjusted to ensure proper protein folding and avoid aggregate formation. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0138] Non-limiting examples of linkers are depicted in Table 3. It should be understood that the linkers are not meant to be particularly limited and any suitable linker may be used, as long as the desired functions (binding, neutralization, etc.) of the polypeptide or binding agent are provided. Table 3: Exemplary linker sequences SEQ ID Linker sequence 68GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS69GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGG70GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGG71GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGG72GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSG73GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS74GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGG75GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGG76GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGG77GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSG78GGGGSGGGGSGGGGSGGGGSGGGGSGGGGS79GGGGSGGGGSGGGGSGGGGSGGGGSGGGG80GGGGSGGGGSGGGGSGGGGSGGGGSGGG81GGGGSGGGGSGGGGSGGGGSGGGGSGG82GGGGSGGGGSGGGGSGGGGSGGGGSG83GGGGSGGGGSGGGGSGGGGSGGGGS84GGGGSGGGGSGGGGSGGGGSGGGG85GGGGSGGGGSGGGGSGGGGSGGG86GGGGSGGGGSGGGGSGGGGSGG87GGGGSGGGGSGGGGSGGGGSG88GGGGSGGGGSGGGGSGGGGS89GGGGSGGGGSGGGGSGGGG90GGGGSGGGGSGGGGSGGG91GGGGSGGGGSGGGGSGG92GGGGSGGGGSGGGGSG93GGGGSGGGGSGGGGS94GGGGSGGGGSGGGG95GGGGSGGGGSGGG96GGGGSGGGGSGG97GGGGSGGGGSG98GGGGSGGGGS99GGGGSGGGG100GGGGSGGG101GGGGSGG102GGGGSG103GGGGS104GGGG105GGG106GG Attorney Docket No.35PH-005 / 03WO 349552-2048 SEQ ID Linker sequence 107TGGG108TGGGG109SGGGG110SGGG111TGGGGSGGGGS112TGGGGSGGGGSGGGGS113TGGGGSGGGGSGGGGSGGGGS114TGGGGSGGGGSGGGGSGGGGSGGGGS115TGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS116TGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS117TGGGPKSCDK118GA119GS120AGGG121GGSG122GGAG123GGGGG124GGGGA125GGGS126GGGA127GGS128GGA129GSGS130GAGAGA131GSGSGS132GAGAGAGA133GSGSGSGS134GAGAGAGAGA135GSGSGSGSGS136GAGAGAGAGAGA137GAGA138GSGSGSGSGSGS139GGAGGA140GGSGGS141GGAGGAGGA142GGSGGSGGS143GGAGGAGGAGGA144GGSGGSGGSGGS145GGAG146GGSG147GGAGGGAG148GGSGGGSG149GGAGGGAGGGAG150GGSGGGSGGGSG151GGGGAGGGGAGGGGA152AAAL153AAAK Attorney Docket No.35PH-005 / 03WO 349552-2048 SEQ ID Linker sequence 154AAAR155EGKSSGSGSESKST156GSAGSAAGSGEF157AEAAAKEAAAKA158KESGSVSSEQLAQFRSLD159GENLYFQSGG160SACYCELS161RSIAT162RPACKIPNDLKQKVMNH163GGSAGGSGSGSSGGSSGASGTGTAGGTGSGSGTGSG164AAANSSIDLISVPVDSR165GGSGGGSEGGGSEGGGSEGGGSEGGGSEGGGSGGGS166EAAAK167PAPAP168GGGAG169GGGAGG170GGGAGGG

[0139] In some embodiments, the ActRIIB ECD variant polypeptide or binding agent of the disclosure comprises one or more linkers having the sequence set forth in any one of SEQ ID NOs: 89, 94, or 98. In some embodiments, the ActRIIB ECD variant polypeptide or binding agent comprises a Glycine-rich linker at the C-terminus of the ActRIIB ECD variant polypeptide that is 2, 3, 6, 10, 14, 19, or 39 amino acids long. In some embodiments, the ActRIIB ECD variant polypeptide or binding agent of the disclosure comprises a linker of SEQ ID NO: 89 at the C-terminus of the ActRIIB ECD variant polypeptide. In some embodiments, the ActRIIB ECD variant polypeptide or binding agent of the disclosure comprises a linker of SEQ ID NO: 94 at the C-terminus of the ActRIIB ECD variant polypeptide. In some embodiments, the ActRIIB ECD variant polypeptide or binding agent of the disclosure comprises a linker of SEQ ID NO: 98 at the C-terminus of the ActRIIB ECD variant polypeptide. Fc domain monomers and Fc domains

[0140] In some embodiments, the present disclosure provides polypeptides comprising an ActRIIB-ECD variant described herein fused, via linker, to an Fc domain monomer. In some embodiments, the ActRIIB-ECD variant is fused at the C-terminus, via a linker, to the N- terminus of the Fc domain monomer.

[0141] As used herein, “Fc domain monomer” describes the single chain protein that, when associated with another Fc domain monomer, forms a functional Fc domain. The association Attorney Docket No.35PH-005 / 03WO 349552-2048 of two Fc domain monomers creates one Fc domain. As used herein, “Fc domain” describes the minimum region (in the context of a larger polypeptide) or smallest protein folded structure (in the context of an isolated protein) that can bind to or be bound by an Fc receptor (FcR). When two Fc domain monomers associate, the resulting Fc domain has Fc receptor binding activity. Thus, an Fc domain is a dimeric structure that can bind an Fc receptor. Unless otherwise noted, all references herein to a “variant Fc domain” are to be understood as referring to a dimeric Fc domain, in which each Fc domain monomer comprises the referenced mutation.

[0142] It will be understood that Fc domain as used herein includes the polypeptides comprising the constant region of an antibody excluding the first constant region immunoglobulin domain. Thus, Fc refers to the last two constant region immunoglobulin domains (CH2, CH3) of IgG and optionally the flexible hinge N-terminal to these domains. Although the boundaries of the Fc domain monomer may vary, the human IgG heavy chain Fc domain monomer is usually defined to comprise residues C226 or P230 to its carboxyl- terminus. Unless otherwise noted, all references to amino acid positions in Fc domains and Fc domain monomers are according to the EU index as set forth in Kabat (1991, NIH Publication 91-3242, National Technical Information Service, Springfield, Va.). Fc may refer to this region in isolation, or this region in the context of a polypeptide construct. It is noted that polymorphisms have been observed at a number of Fc positions, including but not limited to Kabat 270, 272, 312, 315, 356, and 358, and thus slight differences between the sequences provided herein and sequences in the art may exist. The Fc domain monomer included in the polypeptides or binding agents of the present disclosure may be an IgG1, IgG2, IgG3, or IgG4 domain.

[0143] In exemplary embodiments, the polypeptides of the disclosure comprise one or more constant region of an antibody, e.g., the second constant domain (CH2) and / or the third constant domain (CH3) of an antibody heavy chain, or an Fc domain monomer of an antibody heavy chain. The antibody may be, for example and without limitation, an IgG antibody such as an IgG1, IgG2, IgG3 or IgG4 antibody. In particular embodiments, the antibody is a human antibody, e.g., the Fc domain monomer comprises a constant region of the heavy chain of a human IgG1, IgG2, IgG3 or IgG4. In some embodiments, the Fc domain monomer has at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with a human IgG1, IgG2, IgG3 or IgG4 constant region. In a particular embodiment, the Fc domain monomer comprises or consists of an Fc domain monomer of a human IgG1 antibody. In another particular embodiment, the Fc domain monomer comprises Attorney Docket No.35PH-005 / 03WO 349552-2048 or consists of an Fc domain monomer of a human IgG2 antibody. In another particular embodiment, the Fc domain monomer comprises or consists of an Fc domain monomer of a human IgG4 antibody. Exemplary Fc domain sequences (including both wild type sequences, polymorphisms thereof, and variant sequences) are provided in Table 4. Table 4: Exemplary Fc domain sequences Isotype AA Sequence SEQ ID IgG1 – EEM THTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVK 252 polymorph FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIA (“IgG1-EM”) VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG1 – DEL THTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVK 253 polymorph FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIA (“IgG1 –DL”) VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG1 - YTE- THTCPPCPAPELLGGPSVFLFPPKPKDTLYITREPEVTCVVVDVSHEDPEVK 254 EM FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIA VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG1 - YTE- THTCPPCPAPELLGGPSVFLFPPKPKDTLYITREPEVTCVVVDVSHEDPEVK 255 DL FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIA VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG1 - Y-DLTHTCPPCPAPELLGGPSVFLFPPKPKDTLYISRTPEVTCVVVDVSHEDPEVK256 FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIA VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG1 – Y-EMTHTCPPCPAPELLGGPSVFLFPPKPKDTLYISRTPEVTCVVVDVSHEDPEVK257 FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIA VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG1 - DLAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV258 EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK TISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQ KSLSLSPGK IgG1 - DLAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGV259 EVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK TISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQ KSLSLSPG IgG1 - DLPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWY260 VDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPA PIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWE SNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHN HYTQKSLSLSPG IgG1 - DLDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPE261 VKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVS NKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSD Attorney Docket No.35PH-005 / 03WO 349552-2048 Isotype AA Sequence SEQ ID IAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVM HEALHNHYTQKSLSLSPG IgG1 - DLEPKSSDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVS262 HEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEY KCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKG FYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVF SCSVMHEALHNHYTQKSLSLSPG IgG1 - DLEPKSSDKTHTSPPSPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVS263 HEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEY KCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKG FYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVF SCSVMHEALHNHYTQKSLSLSPG IgG1 - EMTHTCPPCPAPELLGGPSVFLFPPKPKDTLYISRTPEVTCVVVDVSHEDPEVK264 FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIA VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG1 – DLTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVK265 FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPVPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIA VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG1 – EMTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVK266 FNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK ALPVPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIA VEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHE ALHNHYTQKSLSLSPG IgG2APPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVE267 VHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAPIEKT ISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDISVEWESNGQP ENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPGK IgG2VECPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFN268 WYVDGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGL PAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVE WESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEAL HNHYTQKSLSLSPGK IgG2ERKCCVECPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP269 EVQFNWYVDGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKV SNKGLPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPS DISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSV MHEALHNHYTQKSLSLSPGK IgG2ERKSSVECPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP270 EVQFNWYVDGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKV SNKGLPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPS DISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSV MHEALHNHYTQKSLSLSPG IgG2ERKSSVESPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP271 EVQFNWYVDGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKV SNKGLPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPS DISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSV MHEALHNHYTQKSLSLSPG IgG2ERKSSVESPPSPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP272 EVQFNWYVDGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKV SNKGLPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPS DISVEWESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSV MHEALHNHYTQKSLSLSPG IgG2APPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYVDGVE273 VHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAPIEKT Attorney Docket No.35PH-005 / 03WO 349552-2048 Isotype AA Sequence SEQ ID ISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDISVEWESNGQP ENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK SLSLSPG IgG2PPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFNWYV274 DGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGLPAP IEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDISVEWES NGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNH YTQKSLSLSPG IgG2VECPPCPAPPVAGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFN275 WYVDGVEVHNAKTKPREEQFNSTFRVVSVLTVVHQDWLNGKEYKCKVSNKGL PAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDISVE WESNGQPENNYKTTPPMLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEAL HNHYTQKSLSLSPG IgG2PCPPCKCPAPNLLGGPSVFIFPPKIKDVLMISLSPIVTCVVVDVSEDDPDVQ276 ISWFVNNVEVHTAQTQTHREDYNSTLRVVSALPIQHQDWMSGKEFKCKVNNK DLPAPIERTISKPKGSVRAPQVYVLPPPEEEMTKKQVTLTCMVTDFMPEDIY VEWTNNGKTELNYKNTEPVLDSDGSYFMYSKLRVEKKNWVERNSYSCSVVHE GLHNHHTTKSFSRTPG IgG3APELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFKWYVDGV277 EVHNAKTKPREEQYNSTFRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK TISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESSGQ PENNYNTTPPMLDSDGSFFLYSKLTVDKSRWQQGNIFSCSVMHEALHNRFTQ KSLSLSPGK IgG3APELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFKWYVDGV278 EVHNAKTKPREEQYNSTFRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK TISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESSGQ PENNYNTTPPMLDSDGSFFLYSKLTVDKSRWQQGNIFSCSVMHEALHNRFTQ KSLSLSPG IgG3PRCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVQFKWY279 VDGVEVHNAKTKPREEQYNSTFRVVSVLTVLHQDWLNGKEYKCKVSNKALPA PIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWE SSGQPENNYNTTPPMLDSDGSFFLYSKLTVDKSRWQQGNIFSCSVMHEALHN RFTQKSLSLSPG IgG3DTPPPCPRCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPE280 VQFKWYVDGVEVHNAKTKPREEQYNSTFRVVSVLTVLHQDWLNGKEYKCKVS NKALPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSD IAVEWESSGQPENNYNTTPPMLDSDGSFFLYSKLTVDKSRWQQGNIFSCSVM HEALHNRFTQKSLSLSPG IgG3EPKSSDTPPPCPRCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVS281 HEDPEVQFKWYVDGVEVHNAKTKPREEQYNSTFRVVSVLTVLHQDWLNGKEY KCKVSNKALPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKG FYPSDIAVEWESSGQPENNYNTTPPMLDSDGSFFLYSKLTVDKSRWQQGNIF SCSVMHEALHNRFTQKSLSLSPG IgG3EPKSSDTPPPSPRCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVS282 HEDPEVQFKWYVDGVEVHNAKTKPREEQYNSTFRVVSVLTVLHQDWLNGKEY KCKVSNKALPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKG FYPSDIAVEWESSGQPENNYNTTPPMLDSDGSFFLYSKLTVDKSRWQQGNIF SCSVMHEALHNRFTQKSLSLSPG IgG3EPKSSDTPPPSPRSPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVS283 HEDPEVQFKWYVDGVEVHNAKTKPREEQYNSTFRVVSVLTVLHQDWLNGKEY KCKVSNKALPAPIEKTISKTKGQPREPQVYTLPPSREEMTKNQVSLTCLVKG FYPSDIAVEWESSGQPENNYNTTPPMLDSDGSFFLYSKLTVDKSRWQQGNIF SCSVMHEALHNRFTQKSLSLSPG IgG4APEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGV284 EVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEK TISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQ KSLSLSLGK Attorney Docket No.35PH-005 / 03WO 349552-2048 Isotype AA Sequence SEQ ID IgG4GPPCPPCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQ285 FNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNK GLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIA VEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHE ALHNHYTQKSLSLSLG IgG4APEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGV286 EVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEK TISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQ PENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQ KSLSLSLG IgG4PSCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWY287 VDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPS SIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWE SNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHN HYTQKSLSLSLG IgG4ESKYGPPCPSCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQED288 PEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCK VSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYP SDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCS VMHEALHNHYTQKSLSLSLG IgG4ESKYGPPCPPCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQED289 PEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCK VSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYP SDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCS VMHEALHNHYTQKSLSLSLG IgG4ESKYGPPCPPCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQED290 PEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCK VSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYP SDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQEGNVFSCS VMHEALHNHYTQKSLSLSLG IgG4ESKYGPPSPSCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQED291 PEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCK VSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYP SDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCS VMHEALHNHYTQKSLSLSLG IgG4ESKYGPPSPSSPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQED292 PEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCK VSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYP SDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCS VMHEALHNHYTQKSLSLSLG

[0144] In general, ActRIIB-ECD polypeptides are organized such that the Fc domain monomer is linked at its N-terminus to the C-terminus of the ActRIIB-ECD variant, so that for each ActRIIB-ECD polypeptide, the orientation of the construct is, from N-terminus to C- terminus, a single chain of (ActRIIB-ECD variant)-(linker)-(Fc domain monomer). However, the orientation of constructs is not particularly limited, and other orientations are contemplated. For example, in some embodiments the Fc domain monomer may be linked at its C-terminus to the N-terminus of the ActRIIB-ECD variant.

[0145] In an exemplary embodiment, the Fc domain monomer allows assembly of two or more polypeptide chains in a covalent manner, for example by disulfide linking between Attorney Docket No.35PH-005 / 03WO 349552-2048 cysteine residues. In this way the Fc domain monomer acts as a dimerization domain, allowing assembly of two ActRIIB-ECD polypeptide chains to form a dimer. In accordance with the present disclosure, such dimers generally comprise two polypeptides, each polypeptide including an ActIIRB-ECD variant linked to the Fc domain monomer as described herein, thereby forming a divalent TGFa superfamily ligand binding agent. The binding agents described herein therefore comprise two ActIIRB-ECD variants, a linker domain, and an Fc domain.

[0146] The Fc domain monomer generally comprises one or more cysteine residue for crosslinking of a first polypeptide with a second polypeptide in a homodimeric construct. For example, the Fc domain monomer may include at least two cysteine residues for forming a disulfide bridge between two polypeptides, thereby forming a dimer. In some embodiments of the present technology, the Fc domain monomer comprises or consists of the sequence set forth in any one of SEQ ID NOs: 252-292, or a sequence at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto. In a particular embodiment, the Fc domain monomer comprises or consists of the amino acid sequence set forth in SEQ ID NO: 253. In a particular embodiment, the Fc domain monomer comprises or consists of the amino acid sequence set forth in SEQ ID NO: 266. In a particular embodiment, the Fc domain monomer comprises or consists of the amino acid sequence set forth in SEQ ID NO: 256. In a particular embodiment, the Fc domain monomer comprises or consists of the amino acid sequence set forth in SEQ ID NO: 255.

[0147] In some embodiments, the present disclosure provides binding agents comprising a variant Fc domain, i.e., a non-naturally occurring Fc domain, for example an Fc domain comprising one or more non-naturally occurring amino acid residue, substitution, addition, deletion, etc.

[0148] In some embodiments of the technology, the Fc domain is a variant Fc domain that forms a variant Fc domain with a desirable property, such as increased half-life, on the polypeptide or binding agent compared to naturally occurring (wild-type) Fc sequences. As used herein, a “variant Fc domain” refers to a non-naturally occurring Fc domain, for example an Fc domain comprising one or more non-naturally occurring amino acid residues, one or more amino acid substitutions relative to a wild-type human constant domain, or one or more amino acid deletion, addition and / or modification. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0149] There are many known polymorphs for the IgG1 Fc domain, including the “DEL” polymorph and the “EEM” polymorph. The DEL polymorph comprises the amino acids D-E- L at positions 356, 357, and 358, respectively (also referred to herein as “Fc-DL”, e.g., SEQ ID NO: 253). The EEM polymorph comprises the amino acids E-E-M at positions 356, 357, and 358, respectively (also referred to herein as “Fc-EM”, e.g., SEQ ID NO: 252). Two binding agents that are otherwise identical except for the presence of a DEL Fc domain or an EEM Fc domain are expected to demonstrate similar properties in terms of ligand binding and therapeutic efficacy. In some embodiments of the technology, the Fc domain is a DEL Fc domain (“DL”). In some embodiments of the technology, the Fc domain is an EEM Fc domain (“EM”). Other polymorphs may also be used, e.g., IgG1 polymorphs of SEQ ID NOs: 252-253 and 258-266, IgG2 polymorphs of SEQ ID NOs: 267-276, IgG3 polymorphs of SEQ ID NOs: 277-283, and IgG4 polymorphs of SEQ ID NOs: 284-292.

[0150] In some embodiments, a variant Fc domain formed by two variant Fc domain monomers has altered binding properties for an Fc receptor such as FcRn, relative to a comparable molecule (e.g., a protein having the same amino acid sequence except having a wild type Fc domain monomer). The serum half-life of proteins comprising Fc domains may be increased by increasing the binding affinity of the Fc domain for FcRn. In one embodiment, the Fc domain variant has enhanced serum half-life relative to a comparable molecule. In a particular embodiment, the Fc domain variant comprises at least one amino acid substitution at one or more positions selected from the group consisting of M252Y, S254T and T256 (referred to herein as “YTE”; e.g., SEQ ID NO: 254 and 255). In another embodiment, the Fc domain variant comprises a Y at position 252 (e.g., SEQ ID NO: 256 and 257, referred to herein as “Fc-Y”). In another embodiment, the Fc domain variant comprises a T at position 254. In another embodiment, the Fc domain variant comprises an E at position 256.

[0151] Consequently, in some embodiments of the present technology, the ActRIIB-ECD polypeptide comprises a variant Fc domain monomer that forms an Fc domain with increased in vivo half-life relative to a comparable molecule. In some such embodiments, the Fc domain monomer of the ActRIIB-ECD polypeptide comprises at least one substitution of an amino acid residue selected from the group consisting of: residue 252, 254, and 256.

[0152] In some embodiments, an ActRIIB-ECD polypeptide comprises a variant Fc domain monomer comprising at least one amino acid substitution selected from the group consisting of M252Y, S254T, and T256E. In such embodiments, the variant Fc domain monomer may Attorney Docket No.35PH-005 / 03WO 349552-2048 further comprise one or more additional amino acid substitution(s) such as, without limitation, E356D and M358L.

[0153] In some embodiments, an ActRIIB-ECD polypeptide comprises a variant Fc domain monomer comprising the following amino acid substitutions: M252Y, S254T, and T256E, referred to herein as “FcYTE” or “YTE”. In some embodiments, the FcYTE domain monomer is a DEL polymorph (referred to herein as YTE-DL, e.g., SEQ ID NO: 255). In some embodiments, the FcYTE domain monomer is an EEM polymorph (referred to herein as YTE- EM, e.g., SEQ ID NO: 254).

[0154] In some embodiments, an ActRIIB-ECD polypeptide comprises a variant Fc domain monomer comprising the following amino acid substitutions: M252Y, referred to herein as “FcY”. In some embodiments, the FcY domain monomer is a DEL polymorph (referred to herein as Y-DL, e.g., SEQ ID NO: 256). In some embodiments, the FcY domain monomer is an EEM polymorph (referred to herein as Y-EM, e.g., SEQ ID NO: 257).

[0155] In some embodiments, an ActRIIB-ECD polypeptide comprises an Fc domain monomer comprising a Lysine residue (K) at the C-terminus.

[0156] In some embodiments, a variant Fc domain (e.g., an Fc domain formed by two variant Fc domain monomers) for use in the ActRIIB-ECD polypeptides of the disclosure comprises one or more amino acid substitution that reduces aggregation and / or increases stability and / or increases half-life of the ActRIIB-ECD polypeptide compared to naturally occurring Fc sequences. In some embodiments, the Fc domain is selected to provide one or more effector function such as antibody dependent cellular cytotoxicity (ADCC), complement activation (complement dependent cytotoxicity or CDC), opsonization, and the like. In an embodiment, a variant Fc domain has enhanced binding to an Fc receptor relative to a comparable molecule. In a specific embodiment, a variant Fc domain has enhanced binding to the neonatal Fc receptor FcRn. In another embodiment, the variant Fc domain and / or the polypeptide or binding agent containing the variant Fc domain has a binding affinity for FcRn that is at least 2 fold, or at least 3 fold, or at least 5 fold, or at least 7 fold, or at least 10 fold, or at least 20 fold, or at least 30 fold, or at least 40 fold, or at least 50 fold, or at least 60 fold, or at least 70 fold, or at least 80 fold, or at least 90 fold, or at least 100 fold, or at least 200 fold greater than that of a comparable molecule. The serum half-life of proteins comprising Fc domain may be increased by increasing the binding affinity of the Fc domain monomer for FcRn. Consequently, in one Attorney Docket No.35PH-005 / 03WO 349552-2048 embodiment the polypeptide or binding agent comprising the variant Fc domain has an enhanced serum half-life relative to a comparable molecule.

[0157] Examples for means to extend serum half-life of the binding agents of the disclosure include peptides, proteins or domains of proteins, which are fused or otherwise attached to the binding agents. The group of peptides, proteins or protein domains includes peptides binding to other proteins with preferred pharmacokinetic profile in the human body such as serum albumin (see WO 2009 / 127691). An alternative concept of such half-life extending peptides includes peptides binding to the neonatal Fc receptor (FcRn, see WO 2007 / 098420), which can also be used in the binding agents of the present disclosure. The concept of attaching larger domains of proteins or complete proteins includes e.g. the fusion of human serum albumin, variants or mutants of human serum albumin (see WO 2011 / 051489, WO 2012 / 059486, WO 2012 / 150319, WO 2013 / 135896, WO 2014 / 072481, WO 2013 / 075066) or domains thereof as well as the fusion of constant region of immunoglobulins (Fc domains) and variants thereof, as described herein. Such variants of Fc domains may be optimized / modified in order to allow the desired pairing of dimers or multimers, to abolish Fc receptor binding (e.g., the Fcg receptor), to enhance binding to FcRn, or for other reasons. A further concept known in the art to extend the half-life of small protein compounds in the human body is the pegylation of those compounds such as the polypeptide or binding agent of the present disclosure.

[0158] In one embodiment, the present disclosure provides binding agents, wherein the Fc domain comprises a non-naturally occurring amino acid residue at one or more positions selected from the group consisting of 234, 235, 236, 237, 238, 239, 240, 241, 243, 244, 245, 247, 251, 252, 254, 255, 256, 262, 263, 264, 265, 266, 267, 268, 269, 279, 280, 284, 292, 296, 297, 298, 299, 305, 313, 316, 325, 326, 327, 328, 329, 330, 332, 333, 334, 339, 341, 343, 370, 373, 378, 392, 416, 419, 421, 440 and 443 as numbered by the EU index as set forth in Kabat. Optionally, the Fc domain may comprise a non-naturally occurring amino acid residue at additional and / or alternative positions known to one skilled in the art (see, e.g., U.S. Pat. Nos. 5,624,821; 6,277,375; 6,737,056; PCT Patent Publications WO 01 / 58957; WO 02 / 06919; WO 04 / 016750; WO 04 / 029207; WO 04 / 035752; WO 04 / 074455; WO 04 / 099249; WO 04 / 063351; WO 05 / 070963; WO 05 / 040217, WO 05 / 092925 and WO 06 / 020114). In a specific embodiment, the present disclosure provides an Fc variant protein composition, wherein the Fc domain comprises at least one amino acid substitution selected from the group consisting of 234D, 234E, 234N, 234Q, 234T, 234H, 234Y, 2341, 234V, 234F, 235A, 235D, 235R.235W, 235P, 235S, 235N, 235Q, 235T, 235H, 235Y, 2351, 235V, 235F, 236E, 239D, 239E, 239N, Attorney Docket No.35PH-005 / 03WO 349552-2048 239Q, 239F, 239T, 239H, 239Y, 240I, 240A, 240T, 240M, 241W, 241 L, 241Y, 241E, 241R. 243W, 243L 243Y, 243R, 243Q, 244H, 245A, 247L, 247V, 247G, 251F, 252Y, 254T, 255L, 256E, 256M, 262I, 262A, 262T, 262E, 2631, 263A, 263T, 263M, 264L, 2641, 264W, 264T, 264R, 264F, 264M, 264Y, 264E, 265G, 265N, 265Q, 265Y, 265F, 265V, 265I, 265L, 265H, 265T, 266I, 266A, 266T, 266M, 267Q, 267L, 268E, 269H, 269Y, 269F, 269R, 270E, 280A, 284M, 292P, 292L, 296E, 296Q, 296D, 296N, 296S, 296T, 296L, 296I, 296H, 269G, 297S, 297D, 297E, 298H, 298I, 298T, 298F, 299I, 299L, 299A, 299S, 299V, 299H, 299F, 299E, 305I, 313F, 316D, 325Q, 325L, 325I, 325D, 325E, 325A, 325T, 325V, 325H, 327G, 327W, 327N, 327L, 328S, 328M, 328D, 328E, 328N, 328Q, 328F, 3281, 328V, 328T, 328H, 328A, 329F, 329H, 329Q, 330K, 330G, 330T, 330C, 330L, 330Y, 330V, 330I, 330F, 330R, 330H, 332D, 332S, 332W, 332F, 332E, 332N, 332Q, 332T, 332H, 332Y, 332A, 339T, 370E, 370N, 378D, 392T, 396L, 416G, 419H, 421K, 440Y and 434W as numbered by the EU index as set forth in Kabat. Optionally, the Fc domain may comprise additional and / or alternative amino acid substitutions known to one skilled in the art (see, e.g., U.S. Pat. Nos.5,624,821; 6,277,375; 6,737,056; PCT Patent Publications WO 01 / 58957; WO 02 / 06919; WO 04 / 016750; WO 04 / 029207; WO 04 / 035752 and WO 05 / 040217). Additional domains

[0159] It is envisaged that the ActRIIB-ECD polypeptide and / or binding agent of the disclosure may have, in addition to its function to bind to the target TGFf superfamily ligand(s) as specified, a further binding specificity or a further function. In some embodiments of the present technology, a ActRIIB-ECD polypeptide or binding agent may be conjugated with a targeting agent, a therapeutic moiety, a detectable moiety and / or a diagnostic moiety. In some embodiments, a polypeptide may possess a further function such as a fully functional Fc constant domain mediating antibody-dependent cellular cytotoxicity through recruitment of effector cells like NK cells, by providing a label (fluorescent etc.), by providing a therapeutic agent such as a toxin or radionuclide, and / or by providing means to enhance serum half-life, etc.

[0160] In some embodiments, the ActRIIB-ECD polypeptides described herein comprise an ActRIIB-ECD, a linker, an Fc domain monomer, and one or more additional domains. In some embodiments, the one or more additional domains is selected from a fibronectin domain, a human serum albumin domain, As used herein, the term "fibronectin domain" refers to a high molecular weight glycoprotein of the extracellular matrix, or a fragment thereof, that binds to, e.g., membrane-spanning receptor proteins such as integrins and extracellular matrix Attorney Docket No.35PH-005 / 03WO 349552-2048 components such as collagens and fibrins. In some embodiments, a fibronectin domain is a fibronectin type III domain having amino acids 610-702 of the sequence of UniProt ID NO: P02751. In other embodiments, a fibronectin domain is an adnectin protein.

[0161] In some embodiments, a polypeptide or binding agent of the disclosure includes an ActRIIB-ECD variant fused to one or more fibronectin domain. Binding to fibronectin domains can improve the pharmacokinetics of protein pharmaceuticals. A fibronectin domain is a high molecular weight glycoprotein of the extracellular matrix, or a fragment thereof, that binds to, e.g., membrane-spanning receptor proteins such as integrins and extracellular matrix components such as collagens and fibrins. In some embodiments of the present invention, a fibronectin domain is joined to the N- or C-terminus (e.g., C-terminus) of an ActRIIB-ECD variant described herein (e.g., an ActRIIB-ECD variant having the amino acid sequence set forth in any one of SEQ ID NOs: 4-62) to increase the serum half-life of the ActRIIB-ECD variant. A fibronectin domain can be joined, either directly or through a linker, to the N- or C- terminus of an ActRIIB-ECD variant, or a polypeptide thereof, or a binding agent thereof. In some embodiments, a polypeptide or binding agent of the disclosure may be fused to the N- or C-terminus of a fibronectin domain, e.g., through conventional genetic or chemical means, e.g., chemical conjugation. If desired, a linker (e.g., a spacer) can be inserted between the ActRIIB- ECD variant and the fibronectin domain. Without being bound by theory, it is expected that in some embodiments inclusion of a fibronectin domain in an ActRIIB-ECD variant described herein may lead to prolonged retention of the therapeutic protein through its binding to integrins and extracellular matrix components such as collagens and fibrins.

[0162] As one example, fibronectin domains that can be used in the methods and compositions and polypeptides of the disclosure are generally known in the art. In one embodiment, the fibronectin domain is a fibronectin type III domain having amino acids 610- 702 of the sequence of UniProt ID NO: P02751. In another embodiment, the fibronectin domain is an adnectin protein.

[0163] As used herein, the term "human serum albumin" refers to the albumin protein present in human blood plasma. Human serum albumin is the most abundant protein in the blood. It constitutes about half of the blood serum protein. In some embodiments, a human serum albumin has the sequence of UniProt ID NO: P02768.

[0164] In some embodiments, an ActRIIB variant or a polypeptide or a binding agent described herein may be fused to serum albumin. Binding to serum albumins can improve the Attorney Docket No.35PH-005 / 03WO 349552-2048 pharmacokinetics of protein pharmaceuticals. Serum albumin is a globular protein that is the most abundant blood protein in mammals. Serum albumin is produced in the liver and constitutes about half of the blood serum proteins. It is monomeric and soluble in the blood. Some of the most crucial functions of serum albumin include transporting hormones, fatty acids, and other proteins in the body, buffering pH, and maintaining osmotic pressure needed for proper distribution of bodily fluids between blood vessels and body tissues. In some embodiments, serum albumin is human serum albumin. In some embodiments, a human serum albumin is joined to the N- or C-terminus (e.g., C-terminus) of an ActRIIB-ECD variant described herein (e.g., an ActRIIB-ECD variant having the amino acid sequence set forth in any one of SEQ ID NOs: 4-62) to increase the serum half-life of the ActRIIB-ECD variant. A human serum albumin can be joined, either directly or through a linker, to the N- or C-terminus of an ActRIIB-ECD variant.

[0165] As one example, serum albumins that can be used in the polypeptides and methods and compositions described herein are generally known in the art. In one embodiment, the serum albumin includes the sequence of UniProt ID NO: P02768. In some embodiments, a polypeptide or binding agent of the disclosure may be fused to the N- or C-terminus of a human serum albumin, e.g., through conventional genetic or chemical means, e.g., chemical conjugation. If desired, a linker (e.g., a spacer) can be inserted between the ActRIIB-ECD variant and the human serum albumin. Without being bound by theory, it is expected that in some embodiments inclusion of a human serum albumin in an ActRIIB-ECD variant described herein may lead to prolonged retention of the therapeutic protein.

[0166] In some embodiments, a polypeptide or binding agent of the disclosure further includes a moiety (e.g., Fc domain monomer, a wild-type Fc domain, an Fc domain with amino acid substitutions (e.g., one or more substitutions that reduce dimerization, an albumin-binding peptide, a fibronectin domain, or a human serum albumin), which may be fused to the N- or C- terminus (e.g., C-terminus) of the ActRIIB-ECD variant, the polypeptide, or the binding agent by way of a linker or other covalent bonds. A polypeptide including an ActRIIB-ECD variant fused to an Fc domain monomer may form a dimer (e.g., homodimer or heterodimer) through the interaction between two Fc domain monomers, which combine to form an Fc domain in the dimer. Furthermore, in some embodiments, a polypeptide or binding agent described herein has a serum half-life of at least 7 days in humans. Attorney Docket No.35PH-005 / 03WO 349552-2048 Exemplary TGF" superfamily binding agents

[0167] The overall structures of exemplary binding agents described herein are provided in Table 5. The amino acid sequences of each binding agent are provided in Table 6. Table 5: Structure of exemplary binding agents Binding ActRII ECD Linker Fc domain SEQ ID agent P75 WT hActRIIB 3 aa IgG1-DL 171 (SEQ ID: 2) (GGG) (SEQ ID: 253) P757 WT hActRIIB 14 aa IgG1-DL 172 (SEQ ID: 2) (SEQ ID:94) (SEQ ID: 253) P444 WT hActRIIA 3 aa IgG1 173 (SEQ ID:3) (GGG) (SEQ ID: 266) P739 hActRIIB G27E 14 aa IgG1-DL 174 (SEQ ID: 4) (SEQ ID: 94) (SEQ ID: 253) P750 hActRIIB L33R 14 aa IgG1-DL 175 (SEQ ID: 15) (SEQ ID: 94) (SEQ ID: 253) P751 hActRIIB L33Y 14 aa IgG1-DL 176 (SEQ ID: 12) (SEQ ID: 94) (SEQ ID: 253) P753 hActRIIB T69H 14 aa IgG1-DL 177 (SEQ ID: 19) (SEQ ID: 94) (SEQ ID: 253) P754 hActRIIB T69Q 14 aa IgG1-DL 178 (SEQ ID: 20) (SEQ ID: 94) (SEQ ID: 253) P765 hActRIIB G27E 3 aa IgG1-DL 179 (SEQ ID: 4) (GGG) (SEQ ID: 253) P777 hActRIIB L33Y 3 aa IgG1-DL 180 (SEQ ID: 12) (GGG) (SEQ ID: 253) P779 hActRIIB T69H 3 aa IgG1-DL 181 (SEQ ID: 19) (GGG) (SEQ ID: 253) P780 hActRIIB T69Q 3 aa IgG1-DL 182 (SEQ ID: 20) (GGG) (SEQ ID: 253) P1171 hActRIIB L33Y T69H 3 aa IgG1-DL 183 (SEQ ID: 28) (GGG) (SEQ ID: 253) P1172 hActRIIB L33Y T69H 10 aa IgG1-DL 184 (SEQ ID: 28) (SEQ ID: 98) (SEQ ID: 253) P1173 hActRIIB L33Y T69H 14 aa IgG1-DL 185 (SEQ ID: 28) (SEQ ID: 94) (SEQ ID: 253) P1174 hActRIIB L33Y T69Q 3 aa IgG1-DL 186 (SEQ ID: 29) (GGG) (SEQ ID: 253) P1175 hActRIIB L33Y T69Q 10 aa IgG1-DL 187 (SEQ ID: 29) (SEQ ID: 98) (SEQ ID: 253) P1176 hActRIIB L33Y T69Q 14 aa IgG1-DL 188 (SEQ ID: 29) (SEQ ID: 94) (SEQ ID: 253) P1177 hActRIIB L33Y T69E 3 aa IgG1-DL 189 (SEQ ID: 30) (GGG) (SEQ ID: 253) P1178 hActRIIB L33Y T69E 10 aa IgG1-DL 190 (SEQ ID: 30) (SEQ ID: 98) (SEQ ID: 253) P1179 hActRIIB L33Y T69E 14 aa IgG1-DL 191 Attorney Docket No.35PH-005 / 03WO 349552-2048 Binding ActRII ECD Linker Fc domain SEQ ID agent (SEQ ID: 30) (SEQ ID: 94) (SEQ ID: 253) P1180 hActRIIB L33Y G27D 3 aa IgG1-DL 192 (SEQ ID: 33) (GGG) (SEQ ID: 253) P1181 hActRIIB L33Y G27D 10 aa IgG1-DL 193 (SEQ ID: 33) (SEQ ID: 98) (SEQ ID: 253) P1182 hActRIIB L33Y G27D 14 aa IgG1-DL 194 (SEQ ID: 33) (SEQ ID: 94) (SEQ ID: 253) P1183 hActRIIB L33Y G27E 3 aa IgG1-DL 195 (SEQ ID: 32) (GGG) (SEQ ID: 253) P1184 hActRIIB L33Y G27E 10 aa IgG1-DL 196 (SEQ ID: 32) (SEQ ID: 98) (SEQ ID: 253) P1185 hActRIIB L33Y G27E 14 aa IgG1-DL 197 (SEQ ID: 32) (SEQ ID: 94) (SEQ ID: 253) P1186 hActRIIB L33F T69Q 3 aa IgG1-DL 198 (SEQ ID: 31) (GGG) (SEQ ID: 253) P1187 hActRIIB L33F T69Q 10 aa IgG1-DL 199 (SEQ ID: 31) (SEQ ID: 98) (SEQ ID: 253) P1188 hActRIIB L33F T69Q 14 aa IgG1-DL 200 (SEQ ID: 31) (SEQ ID: 94) (SEQ ID: 253) P1201 hActRIIB T69E 3 aa IgG1-DL 201 (SEQ ID: 21) (GGG) (SEQ ID: 253) P1202 hActRIIB T69E 10 aa IgG1-DL 202 (SEQ ID: 21) (SEQ ID: 98) (SEQ ID: 253) P1203 hActRIIB T69E 14 aa IgG1-DL 203 (SEQ ID: 21) (SEQ ID: 94) (SEQ ID: 253) P1204 hActRIIB L33F 3 aa IgG1-DL 204 (SEQ ID: 10) (GGG) (SEQ ID: 253) P1205 hActRIIB L33F 10 aa IgG1-DL 205 (SEQ ID: 10) (SEQ ID: 98) (SEQ ID: 253) P1206 hActRIIB L33F 14 aa IgG1-DL 206 (SEQ ID: 10) (SEQ ID: 94) (SEQ ID: 253) P1207 hActRIIB L33Q 3 aa IgG1-DL 207 (SEQ ID: 11) (GGG) (SEQ ID: 253) P1208 hActRIIB L33Q 10 aa IgG1-DL 208 (SEQ ID: 11) (SEQ ID: 98) (SEQ ID: 253) P1209 hActRIIB L33Q 14 aa IgG1-DL 209 (SEQ ID: 11) (SEQ ID: 94) (SEQ ID: 253) P1210 hActRIIB L33Y 10 aa IgG1-DL 210 (SEQ ID: 12) (SEQ ID: 98) (SEQ ID: 253) P1229 hActRIIB L33W 14 aa IgG1-DL 211 (SEQ ID: 13) (SEQ ID: 94) (SEQ ID: 253) P1230 hActRIIB L33E 14 aa IgG1-DL 212 (SEQ ID: 16) (SEQ ID:94) (SEQ ID: 253) P1231 hActRIIB L33K 14 aa IgG1-DL 213 (SEQ ID: 17) (SEQ ID: 94) (SEQ ID: 253) P1232 hActRIIB L33M 14 aa IgG1-DL 214 (SEQ ID: 18) (SEQ ID: 94) (SEQ ID: 253) Attorney Docket No.35PH-005 / 03WO 349552-2048 Binding ActRII ECD Linker Fc domain SEQ ID agent P1235 hActRIIB L33Y G27N 14 aa IgG1-DL 215 (SEQ ID: 34) (SEQ ID: 94) (SEQ ID: 253) P1236 hActRIIB L33Y G27Q 14 aa IgG1-DL 216 (SEQ ID: 35) (SEQ ID: 94) (SEQ ID: 253) P1237 hActRIIB L33Y G27K 14 aa IgG1-DL 217 (SEQ ID: 36) (SEQ ID: 94) (SEQ ID: 253) P1238 hActRIIB L33Y G27T 14 aa IgG1-DL 218 (SEQ ID: 37) (SEQ ID: 94) (SEQ ID: 253) P1239 hActRIIB L33Y G27M 14 aa IgG1-DL 219 (SEQ ID: 38) (SEQ ID: 94) (SEQ ID: 253) P1240 hActRIIB L33Y T69R 14 aa IgG1-DL 220 (SEQ ID: 25) (SEQ ID: 94) (SEQ ID: 253) P1241 hActRIIB L33Y T69Y 14 aa IgG1-DL 221 (SEQ ID: 26) (SEQ ID: 94) (SEQ ID: 253) P1242 hActRIIB L33Y T69W 14 aa IgG1-DL 222 (SEQ ID: 27) (SEQ ID: 94) (SEQ ID: 253) P1269 hActRIIB L33Y, L14E 14 aa IgG1-DL 223 (SEQ ID: 52) (SEQ ID: 94) (SEQ ID: 253) P1270 hActRIIB L33Y, L14H 14 aa IgG1-DL 224 (SEQ ID: 53) (SEQ ID: 94) (SEQ ID: 253) P1271 hActRIIB L33Y, L14S 14 aa IgG1-DL 225 (SEQ ID: 54) (SEQ ID: 94) (SEQ ID: 253) P1272 hActRIIB L33Y, L55Y 14 aa IgG1-DL 226 (SEQ ID: 59) (SEQ ID: 94) (SEQ ID: 253) P1273 hActRIIB L33Y, L55Q 14 aa IgG1-DL 227 (SEQ ID: 60) (SEQ ID: 94) (SEQ ID: 253) P1274 hActRIIB L33Y, L55M 14 aa IgG1-DL 228 (SEQ ID: 61) (SEQ ID: 94) (SEQ ID: 253) P1275 hActRIIB L33Y, L55I 14 aa IgG1-DL 229 (SEQ ID: 62) (SEQ ID: 94) (SEQ ID: 253) P1371 hActRIIB L33W 14 aa IgG1 Y-DL 230 (SEQ ID: 13) (SEQ ID: 94) (SEQ ID: 256) P1372 hActRIIB L33W 14 aa IgG1 YTE-DL 231 (SEQ ID: 13) (SEQ ID: 94) (SEQ ID: 255) P1373 hActRIIB L33W 19 aa IgG1-DL 232 (SEQ ID: 13) (SEQ ID: 89) (SEQ ID: 253) P1374 hActRIIB L33W 19 aa IgG1 Y-DL 233 (SEQ ID: 13) (SEQ ID: 89) (SEQ ID: 256) P1375 hActRIIB L33W 19 aa IgG1 YTE-DL 234 (SEQ ID: 13) (SEQ ID: 89) (SEQ ID: 255) P1385 hActRIIB G27D, L33W 19 aa IgG1-DL 235 (SEQ ID: 43) (SEQ ID: 89) (SEQ ID: 253) P1386 hActRIIB G27E, L33W 19 aa IgG1-DL 236 (SEQ ID: 44) (SEQ ID: 89) (SEQ ID: 253) P1387 hActRIIB G27N, L33W 19 aa IgG1-DL 237 (SEQ ID: 45) (SEQ ID: 89) (SEQ ID: 253) P1388 hActRIIB G27Q, L33W 19 aa IgG1-DL 238 Attorney Docket No.35PH-005 / 03WO 349552-2048 Binding ActRII ECD Linker Fc domain SEQ ID agent (SEQ ID: 46) (SEQ ID: 89) (SEQ ID: 253) P1389 hActRIIB G27T, L33W 19 aa IgG1-DL 239 (SEQ ID: 47) (SEQ ID: 89) (SEQ ID: 253) P1390 hActRIIB G27M, L33W 19 aa IgG1-DL 240 (SEQ ID: 48) (SEQ ID: 89) (SEQ ID: 253) P1391 hActRIIB G27D, L33Y 19 aa IgG1-DL 241 (SEQ ID: 39) (SEQ ID: 89) (SEQ ID: 253) P1392 hActRIIB G27E, L33Y 19 aa IgG1-DL 242 (SEQ ID: 40) (SEQ ID: 89) (SEQ ID: 253) P1395 hActRIIB G27N, L33Y 19 aa IgG1-DL 243 (SEQ ID: 41) (SEQ ID: 89) (SEQ ID: 253) P1396 hActRIIB G27Q, L33Y 19 aa IgG1-DL 244 (SEQ ID: 42) (SEQ ID: 89) (SEQ ID: 253) P1406 hActRIIB L14E, L33W 19 aa IgG1-DL 245 (SEQ ID: 55) (SEQ ID: 89) (SEQ ID: 253) P1407 hActRIIB L14D, L33W 19 aa IgG1-DL 246 (SEQ ID: 56) (SEQ ID: 89) (SEQ ID: 253) P1408 hActRIIB L14N, L33W 19 aa IgG1-DL 247 (SEQ ID: 57) (SEQ ID: 89) (SEQ ID: 253) P1409 hActRIIB L14Q, L33W 19 aa IgG1-DL 248 (SEQ ID: 58) (SEQ ID: 89) (SEQ ID: 253) P1410 hActRIIB L14Q, L33Y 19 aa IgG1-DL 249 (SEQ ID: 49) (SEQ ID: 89) (SEQ ID: 253) P1411 hActRIIB L14D, L33Y 19 aa IgG1-DL 250 (SEQ ID: 50) (SEQ ID: 89) (SEQ ID: 253) P1412 hActRIIB L14N, L33Y 19 aa IgG1-DL 251 (SEQ ID: 51) (SEQ ID: 89) (SEQ ID: 253) Table 6: Exemplary binding agent amino acid sequences Agent AA Sequence SEQ ID P75ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC171 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P757ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC172 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P444ILGRSETQECLFFNANWEKDRTNQTGVEPCYGDKDKRRHCFATWKNISGSIEIVKQGCWL173 DDINCYDRTDCVEKKDSPEVYFCCCEGNMCNEKFSYFPEMEVTQPTSNPVTPKPPTGGGT HTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVE VHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPVPIEKTISKAKGQP REPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGS FFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID P739ETRECIYYNANWELERTNQSGLERCEEEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC174 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P750ETRECIYYNANWELERTNQSGLERCEGEQDKRRHCYASWRNSSGTIELVKKGCWLDDFNC175 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P751ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC176 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P753ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC177 YDRQECVAHEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P754ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC178 YDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P765ETRECIYYNANWELERTNQSGLERCEEEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC179 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P777ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC180 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P779ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC181 YDRQECVAHEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P780ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC182 YDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1171ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC183 YDRQECVAHEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1172ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC184 YDRQECVAHEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1173ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC185 YDRQECVAHEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1174ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC186 YDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1175ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC187 YDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1176ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC188 YDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1177ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC189 YDRQECVAEEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1178ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC190 YDRQECVAEEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1179ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC191 YDRQECVAEEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1180ETRECIYYNANWELERTNQSGLERCEDEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC192 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1181ETRECIYYNANWELERTNQSGLERCEDEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC193 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1182ETRECIYYNANWELERTNQSGLERCEDEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC194 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1183ETRECIYYNANWELERTNQSGLERCEEEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC195 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1184ETRECIYYNANWELERTNQSGLERCEEEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC196 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1185ETRECIYYNANWELERTNQSGLERCEEEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC197 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1186ETRECIYYNANWELERTNQSGLERCEGEQDKRFHCYASWRNSSGTIELVKKGCWLDDFNC198 YDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1187ETRECIYYNANWELERTNQSGLERCEGEQDKRFHCYASWRNSSGTIELVKKGCWLDDFNC199 YDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1188ETRECIYYNANWELERTNQSGLERCEGEQDKRFHCYASWRNSSGTIELVKKGCWLDDFNC200 YDRQECVAQEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1201ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC201 YDRQECVAEEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1202ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC202 YDRQECVAEEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID P1203ETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSGTIELVKKGCWLDDFNC203 YDRQECVAEEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1204ETRECIYYNANWELERTNQSGLERCEGEQDKRFHCYASWRNSSGTIELVKKGCWLDDFNC204 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1205ETRECIYYNANWELERTNQSGLERCEGEQDKRFHCYASWRNSSGTIELVKKGCWLDDFNC205 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1206ETRECIYYNANWELERTNQSGLERCEGEQDKRFHCYASWRNSSGTIELVKKGCWLDDFNC206 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1207ETRECIYYNANWELERTNQSGLERCEGEQDKRQHCYASWRNSSGTIELVKKGCWLDDFNC207 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGTHTCPPCPAP ELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPR EEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLP PSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTV DKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1208ETRECIYYNANWELERTNQSGLERCEGEQDKRQHCYASWRNSSGTIELVKKGCWLDDFNC208 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1209ETRECIYYNANWELERTNQSGLERCEGEQDKRQHCYASWRNSSGTIELVKKGCWLDDFNC209 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1210ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC210 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSTHT CPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVH NAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPRE PQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFF LYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1229ETRECIYYNANWELERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC211 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1230ETRECIYYNANWELERTNQSGLERCEGEQDKREHCYASWRNSSGTIELVKKGCWLDDFNC212 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1231ETRECIYYNANWELERTNQSGLERCEGEQDKRKHCYASWRNSSGTIELVKKGCWLDDFNC213 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1232ETRECIYYNANWELERTNQSGLERCEGEQDKRMHCYASWRNSSGTIELVKKGCWLDDFNC214 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1235ETRECIYYNANWELERTNQSGLERCENEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC215 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1236ETRECIYYNANWELERTNQSGLERCEQEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC216 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1237ETRECIYYNANWELERTNQSGLERCEKEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC217 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1238ETRECIYYNANWELERTNQSGLERCETEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC218 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1239ETRECIYYNANWELERTNQSGLERCEMEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC219 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1240ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC220 YDRQECVAREENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1241ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC221 YDRQECVAYEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1242ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC222 YDRQECVAWEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1269ETRECIYYNANWEEERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC223 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1270ETRECIYYNANWEHERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC224 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1271ETRECIYYNANWESERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC225 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1272ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWYDDFNC226 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1273ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWQDDFNC227 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1274ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWMDDFNC228 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1275ETRECIYYNANWELERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWIDDFNC229 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1371ETRECIYYNANWELERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC230 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLYISRTPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1372ETRECIYYNANWELERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC231 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GTHTCPPCPAPELLGGPSVFLFPPKPKDTLYITREPEVTCVVVDVSHEDPEVKFNWYVDG VEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSD GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID P1373ETRECIYYNANWELERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC232 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1374ETRECIYYNANWELERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC233 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLYISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1375ETRECIYYNANWELERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC234 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLYITREPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1385ETRECIYYNANWELERTNQSGLERCEDEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC235 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1386ETRECIYYNANWELERTNQSGLERCEEEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC236 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1387ETRECIYYNANWELERTNQSGLERCENEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC237 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1388ETRECIYYNANWELERTNQSGLERCEQEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC238 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1389ETRECIYYNANWELERTNQSGLERCETEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC239 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1390ETRECIYYNANWELERTNQSGLERCEMEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC240 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1391ETRECIYYNANWELERTNQSGLERCEDEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC241 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1392ETRECIYYNANWELERTNQSGLERCEEEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC242 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1395ETRECIYYNANWELERTNQSGLERCENEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC243 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1396ETRECIYYNANWELERTNQSGLERCEQEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC244 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1406ETRECIYYNANWEEERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC245 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1407ETRECIYYNANWEDERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC246 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1408ETRECIYYNANWENERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC247 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1409ETRECIYYNANWEQERTNQSGLERCEGEQDKRWHCYASWRNSSGTIELVKKGCWLDDFNC248 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1410ETRECIYYNANWEQERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC249 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1411ETRECIYYNANWEDERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC250 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG P1412ETRECIYYNANWENERTNQSGLERCEGEQDKRYHCYASWRNSSGTIELVKKGCWLDDFNC251 YDRQECVATEENPQVYFCCCEGNFCNERFTHLPEAGGPEVTYEPPPTGGGGSGGGGSGGG Attorney Docket No.35PH-005 / 03WO 349552-2048 Agent AA Sequence SEQ ID GSGGGGTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFN WYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTI SKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPP VLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG *Bold and italicized text indicates the linker sequence; Bold text indicates the N-terminal extension amino acids

[0168] In some embodiments, the binding agent comprises, from N-terminus to C-terminus, an ActRIIB ECD, a peptide linker, and an Fc domain. In some embodiments, the ActRIIB ECD comprises one or more amino acid substitutions. In some embodiments, the one or more amino acid substitutions are substitutions at a position selected from L14, G27, L33, L55, and L69, wherein the amino acid numbering is based on SEQ ID NO: 2. In some embodiments, the amino acid substitution at position L14 is selected from L14E, L14H, L14S, L14N, L14Q, and L14D. In some embodiments, the amino acid substitution at position G27 is selected from G27E, G27D, G27N, G27Q, G27Q, G27K, G27T, and G27M. In some embodiments, the amino acid substitution at position L33 is selected from L33R, L33Y, L33F, L33Q, L33W, L33E, L33K, and L33M. In some embodiments, the amino acid substitution at position L55 is selected from L55Y, L55Q, L55M, and L55I. In some embodiments, the amino acid substitution at position T69 is selected from T69H, T69Q, T69E, T69R, T69Y, and T69W.

[0169] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of G27E, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 4, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 4, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 174 (P739). In some embodiments the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN Attorney Docket No.35PH-005 / 03WO 349552-2048 polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 174 (P739).

[0170] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33R, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 15, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 15, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 175 (P750). In some embodiments the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 175 (P750).

[0171] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33Y, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 12, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 12, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 176 (P751). In some embodiments, Attorney Docket No.35PH-005 / 03WO 349552-2048 XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 176 (P751).

[0172] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of T69H, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 19, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 19, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 177 (P753). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 177 (P753).

[0173] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of T69Q, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 20, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 20, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least Attorney Docket No.35PH-005 / 03WO 349552-2048 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 178 (P754). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 178 (P754).

[0174] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of G27E, a peptide linker that is 3aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 4, a peptide linker that is 3aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 4, a peptide linker that is 3aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 179 (P765). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 179 (P765).

[0175] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33Y, a peptide linker that is 3aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 12, a peptide linker that is 3aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 12, a peptide linker that is 3aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI Attorney Docket No.35PH-005 / 03WO 349552-2048 polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 180 (P777). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 180 (P777).

[0176] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of T69H, a peptide linker that is 3aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 19, a peptide linker that is 3aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 19, a peptide linker that is 3aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 181 (P779). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 181 (P779).

[0177] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of T69Q, a peptide linker that is 3aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 20, a peptide linker that is 3aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 20, a peptide linker that is 3aa in length, and an IgG1-DL Fc domain Attorney Docket No.35PH-005 / 03WO 349552-2048 monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 182 (P780). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 182 (P780).

[0178] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and T69H, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 28, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 28, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 183 (P1171). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 183 (P1171). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 184 (P1172). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 184 (P1172). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 185 (P1173). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 185 (P1173). Attorney Docket No.35PH-005 / 03WO 349552-2048

[0179] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and T69Q, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 29, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 29, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 186 (P1174). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 186 (P1174). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 187 (P1175). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 187 (P1175). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 188 (P1176). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 188 (P1176).

[0180] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and T69E, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN Attorney Docket No.35PH-005 / 03WO 349552-2048 polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 30, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 30, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 189 (P1177). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 189 (P1177). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 190 (P1178). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 190 (P1178). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 191 (P1179). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 191 (P1179).

[0181] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and G27D, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 33, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 33, a Attorney Docket No.35PH-005 / 03WO 349552-2048 peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 192 (P1180). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 192 (P1180). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 193 (P1181). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 193 (P1181). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 194 (P1182). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 194 (P1182).

[0182] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and G27E, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 32, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 32, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 195 (P1183). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 195 (P1183). In some Attorney Docket No.35PH-005 / 03WO 349552-2048 embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 196 (P1184). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 196 (P1184). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 197 (P1185). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 197 (P1185).

[0183] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33F and T69Q, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 31, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 31, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 198 (P1186). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 198 (P1186). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 199 (P1187). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 199 (P1187). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' Attorney Docket No.35PH-005 / 03WO 349552-2048 wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 200 (P1188). In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 200 (P1188).

[0184] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of T69E, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 21, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 21, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 201 (P1201). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 201 (P1201). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 202 (P1202). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 202 (P1202). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 203 (P1203). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 203 (P1203).

[0185] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an Attorney Docket No.35PH-005 / 03WO 349552-2048 ActRIIB ECD comprising the amino acid substitution of L33F, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 10, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 10, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 204 (P1204). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 204 (P1204). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 205 (P1205). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 205 (P1205). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 206 (P1206). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 206 (P1206).

[0186] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33Q, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 11, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some Attorney Docket No.35PH-005 / 03WO 349552-2048 embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 11, a peptide linker that is 3aa, 10aa, or 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 207 (P1207). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 207 (P1207). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 208 (P1208). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 208 (P1208). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 209 (P1209). In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 209 (P1209).

[0187] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33Y, a peptide linker that is 10aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 12, a peptide linker that is 10aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 12, a peptide linker that is 10aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 210 (P1210). In some embodiments, Attorney Docket No.35PH-005 / 03WO 349552-2048 XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 210 (P1210).

[0188] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33W, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 13, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 13, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 211 (P1229). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 211 (P1229).

[0189] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33E, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 16, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 16, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least Attorney Docket No.35PH-005 / 03WO 349552-2048 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 212 (P1230). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 212 (P1230).

[0190] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33K, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 17, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 17, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 213 (P1231). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 213 (P1231).

[0191] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33M, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 18, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 18, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI Attorney Docket No.35PH-005 / 03WO 349552-2048 polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 214 (P1232). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 214 (P1232).

[0192] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and G27N, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 34, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 34, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 215 (P1235). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 215 (P1235).

[0193] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and G27Q, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 35, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 35, a peptide linker that is 14aa in length, Attorney Docket No.35PH-005 / 03WO 349552-2048 and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 216 (P1236). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 216 (P1236).

[0194] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and G27K, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 36, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 36, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 217 (P1237). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 217 (P1237).

[0195] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and G27Y, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 37, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or Attorney Docket No.35PH-005 / 03WO 349552-2048 consisting of the amino acid sequence of SEQ ID NO: 37, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 218 (P1238). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 218 (P1238).

[0196] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and G27M, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 38, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 38, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 219 (P1239). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 219 (P1239).

[0197] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and T69R, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 25, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN Attorney Docket No.35PH-005 / 03WO 349552-2048 polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 25, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 220 (P1240). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 220 (P1240).

[0198] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and T69Y, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 26, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 26, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 221 (P1241). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 221 (P1241).

[0199] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and T69W, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 27, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the Attorney Docket No.35PH-005 / 03WO 349552-2048 E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 27, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 222 (P1242). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 222 (P1242).

[0200] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and L14E, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 52, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 52, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 223 (P1269). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 223 (P1269).

[0201] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and L14H, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 53, a peptide Attorney Docket No.35PH-005 / 03WO 349552-2048 linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 53, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 224 (P1270). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 224 (P1270).

[0202] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and L14S, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 54, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 54, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 225 (P1271). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 225 (P1271).

[0203] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and L55Y, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid Attorney Docket No.35PH-005 / 03WO 349552-2048 sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 59, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 59, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 226 (P1272). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 226 (P1272).

[0204] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and L55Q, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 60, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 60, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 227 (P1273). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 227 (P1273).

[0205] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and L55M, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide Attorney Docket No.35PH-005 / 03WO 349552-2048 chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 61, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 61, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 228 (P1274). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 228 (P1274). In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L33Y and L55I, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 62, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 62, a peptide linker that is 14aa in length, and an IgG1-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 229 (P1275). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 229 (P1275).

[0206] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33W, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ Attorney Docket No.35PH-005 / 03WO 349552-2048 binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 13, a peptide linker that is 14aa in length, and an IgG1 Y-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 13, a peptide linker that is 14aa in length, and an IgG1 Y-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 230 (P1371). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 230 (P1371).

[0207] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33W, a peptide linker that is 14aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 13, a peptide linker that is 14aa in length, and an IgG1 YTE-DL Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 13, a peptide linker that is 14aa in length, and an IgG1 YTE-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 231 (P1372). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 231 (P1372).

[0208] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33W, a peptide linker that is 19aa in Attorney Docket No.35PH-005 / 03WO 349552-2048 length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 13, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 13, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 232 (P1373). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 232 (P1373).

[0209] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitution of L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 13, a peptide linker that is 19aa in length, and an IgG1 Y-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 13, a peptide linker that is 19aa in length, and an IgG1 Y-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 233 (P1374). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 233 (P1374).

[0210] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an Attorney Docket No.35PH-005 / 03WO 349552-2048 ActRIIB ECD comprising the amino acid substitution of L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 13, a peptide linker that is 19aa in length, and an IgG1 YTE-DL Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 13, a peptide linker that is 19aa in length, and an IgG1 YTE-DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 234 (P1375). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 234 (P1375).

[0211] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27D and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 43, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 43, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 235 (P1385). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 235 (P1385). Attorney Docket No.35PH-005 / 03WO 349552-2048

[0212] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27E and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 44, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 44, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 236 (P1386). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 236 (P1386).

[0213] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27N and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 45, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 45, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 237 (P1387). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G Attorney Docket No.35PH-005 / 03WO 349552-2048 homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 237 (P1387).

[0214] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27Q and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 46, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 46, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 238 (P1388). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 238 (P1388).

[0215] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27T and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 47, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 47, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: Attorney Docket No.35PH-005 / 03WO 349552-2048 239 (P1389). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 239 (P1389).

[0216] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27M and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 48, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 48, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 240 (P1390). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 240 (P1390).

[0217] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27D and L33Y, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 39, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 39, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an Attorney Docket No.35PH-005 / 03WO 349552-2048 amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 241 (P1391). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 241 (P1391).

[0218] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27E and L33Y, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 40, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 40, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 242 (P1392). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 242 (P1392).

[0219] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27N and L33Y, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 41, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 41, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ Attorney Docket No.35PH-005 / 03WO 349552-2048 binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 243 (P1395). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 243 (P1395).

[0220] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of G27Q and L33Y, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 42, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 42, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 244 (P1396). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 244 (P1396).

[0221] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L14E and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 55, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 55, a peptide linker that is 19aa in length, Attorney Docket No.35PH-005 / 03WO 349552-2048 and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 245 (P1406). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 245 (P1406).

[0222] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L14D and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 56, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 56, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 246 (P1407). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 246 (P1407).

[0223] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L14N and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 57, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or Attorney Docket No.35PH-005 / 03WO 349552-2048 consisting of the amino acid sequence of SEQ ID NO: 57, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 247 (P1408). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 247 (P1408).

[0224] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L14Q and L33W, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 58, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 58, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 248 (P1409). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 248 (P1409).

[0225] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L14Q and L33Y, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 49, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN Attorney Docket No.35PH-005 / 03WO 349552-2048 polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 49, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 249 (P1410). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 249 (P1410).

[0226] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L14D and L33Y, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 50, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 50, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 250 (P1411). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 250 (P1411).

[0227] In some embodiments XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising the amino acid substitutions of L14N and L33Y, a peptide linker that is 19aa in length, and an IgG1 Fc domain monomer. In some embodiments, XNK E<;a superfamily ligand binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 51, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, the Attorney Docket No.35PH-005 / 03WO 349552-2048 E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G NTRTJORKVOI UTQ]UKUXOJK' [NKVKOS KGIN polypeptide chain comprises from N-terminus to C-terminus, an ActRIIB ECD comprising or consisting of the amino acid sequence of SEQ ID NO: 51, a peptide linker that is 19aa in length, and an IgG1 DL Fc domain monomer. In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ binding agent is a homodimeric polypeptide, wherein each polypeptide chain comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 251 (P1412). In some embodiments, XNK E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX OW G homodimeric polypeptide, wherein each polypeptide chain comprises or consists of the amino acid sequence of SEQ ID NO: 251 (P1412).

[0228] In some embodiments, the polypeptides or binding agents of the disclosure are "isolated" or "substantially pure". "Isolated" or "substantially pure", when used to describe the polypeptides or binding agents disclosed herein, means a polypeptide or binding agent that has been identified, separated and / or recovered from a component of its production environment. Preferably, the polypeptide or binding agent is free or substantially free of association with all other components from its production environment. Contaminant components of its production environment, such as that resulting from recombinant transfected cells, are materials that would typically interfere with diagnostic or therapeutic uses for the polypeptide, and may include enzymes, hormones, and other proteinaceous or non-proteinaceous solutes. The polypeptides or binding agents may, e.g., constitute at least about 5%, or at least about 50% by weight of the total protein in a given sample. It is understood that the isolated protein may constitute from 5% to 99.9% by weight of the total protein content, depending on the circumstances. The polypeptide or binding agent may be made at a significantly higher concentration through the use of an inducible promoter or high expression promoter, such that it is made at increased concentration levels. The definition includes the production of a polypeptide or binding agent in a wide variety of organisms and / or host cells that are known in the art. In preferred embodiments, the polypeptide or binding agent will be purified (1) to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or (2) to homogeneity by SDS-PAGE under non-reducing or reducing conditions using Coomassie blue or, preferably, silver stain. Ordinarily, however, an isolated polypeptide or binding agent will be prepared by at least one purification step, such as, for example and without limitation, affinity and / or ion-exchange chromatography, e.g., binding to a Protein A column. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0229] In some embodiments, binding agents of the present disclosure are characterized, for example, by one or more of the following: a particularly high affinity for one or more of activin A, activin B, GDF-8, and GDF-11; high neutralization potency (low IC50 values) for one or more of activin A, activin B, GDF-8, and GDF-11; a particularly low or undetectable affinity for BMP-9 and / or BMP-10; low or not detectable neutralization potency (high IC50 value) for BMP-9 and / or BMP-10; high thermostability; high plasma stability; long or extended half-life, low turbidity; high protein homogeneity; and / or high manufacturability.

[0230] The biological activity of a polypeptide or binding agent, or pharmaceutical composition thereof, of the disclosure can be determined for instance by cellular neutralization assays, binding assays, competition assays and the like. "Efficacy" or "in vivo efficacy" as used herein refers to the response to therapy using a combination described herein or composition thereof. The success or in vivo efficacy of the therapy using a combination described herein or composition thereof refers to the effectiveness of the combination or composition for its intended purpose, e.g., the ability of the combination described herein or composition thereof to cause its desired effect, i.e. treatment, amelioration, or prevention of a metabolic disorder. The in vivo efficacy may be monitored by established standard methods for the respective disease entities. In addition, various disease specific clinical chemistry parameters and other established standard methods may be used.

[0231] Another major challenge in the development of drugs such as a pharmaceutical composition of the disclosure is the predictable modulation of pharmacokinetic properties. To this end, a pharmacokinetic profile of the drug candidate, i.e., a profile of the pharmacokinetic parameters that affect the ability of a particular drug to treat a given condition, can be established. Pharmacokinetic parameters of the drug influencing the ability of a drug for treating a certain disease entity include, but are not limited to: half-life, volume of distribution, hepatic first-pass metabolism and the degree of blood serum binding. The efficacy of a given drug agent can be influenced by each of the parameters mentioned above.

[0232] Pharmacokinetic parameters also include bioavailability, lag time (Tlag), Tmax, absorption rates, more onset and / or Cmax for a given amount of drug administered. "Bioavailability" means the amount of a drug in the blood compartment. "Lag time" means the time delay between the administration of the drug and its detection and measurability in blood or plasma. "Tmax" is the time after which maximal blood concentration of the drug is reached, and "Cmax" is the blood concentration maximally obtained with a given drug. The time to Attorney Docket No.35PH-005 / 03WO 349552-2048 reach a blood or tissue concentration of the drug which is required for its biological effect is influenced by all parameters.

[0233] In some embodiments, the binding agent of the present disclosure has a half-life of about 3 days or longer, about 5 days or longer, about 1 week or longer, about 2 weeks or longer, about 3 weeks or longer, about 4 weeks or longer, about 5 weeks or longer, about 6 weeks or longer, or about two months or longer.

[0234] In some embodiments, the binding agent of the present disclosure may show a favorable thermostability with aggregation temperatures of about 45oC or higher, about 45 to about 50oC, about 52-about 54oC, about 56 to about 60oC, or about 60oC or higher. The thermostability parameter can be determined in terms of polypeptide aggregation temperature as follows: Protein solution at a test concentration (e.g., 100 $qg / ml, 250 $qg / ml) is transferred into a single use cuvette and placed in a Dynamic Light Scattering (DLS) device. The sample is heated from 40oC to 70oC at a heating rate of 0.5oC / min with constant acquisition of the measured radius. Increase of radius indicating melting of the protein and aggregation is used to calculate the aggregation temperature of the polypeptide. Other methods known in the art may be used.

[0235] In an embodiment the binding agent according to the disclosure is stable at 2-8oC for at least 1 month, 2 months, or 3 months. In an embodiment the polypeptide or binding agent according to the disclosure is stable at 25-40oC for at least 4 weeks. In an embodiment the binding agent according to the disclosure is stable after undergoing 3 Freeze / Thaw cycles. In an embodiment the binding agent according to the disclosure is stable at -20oC for 1 month, 2 month, 3 months or longer.

[0236] Alternatively, temperature melting curves can be determined by Differential Scanning Calorimetry (DSC) to determine intrinsic biophysical protein stabilities of the polypeptides or binding agents. These experiments may be performed using a MicroCal LLC (Northampton, Mass., U.S.A) VP-DSC device. The energy uptake of a sample containing a binding agent is recorded from 20oC to 90oC compared to a sample containing only the formulation buffer. For recording of the respective melting curve, the overall sample temperature is increased stepwise. At each temperature T energy uptake of the sample and the formulation buffer reference is recorded. The difference in energy uptake Cp (kcal / mole / oC) of the sample minus the reference is plotted against the respective temperature. The melting temperature is defined as the temperature at the first maximum of energy uptake. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0237] In a further embodiment, binding agents according to the disclosure are stable at acidic pH. The more tolerant the binding agent behaves at unphysiologic pH such as pH 5.5 (a pH which is required to run e.g. a cation exchange chromatography), the higher is the recovery of binding agent eluted from an ion exchange column relative to the total amount of loaded protein. Recovery of binding agents from an ion (e.g., cation) exchange column at pH 5.5 may be 50% or more, 60% or more, 65% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 90% or more, 95% or more, or 99% or more. Amino acid sequence modifications

[0238] Amino acid sequence modifications of the binding agents described herein are contemplated. For example, it may be desirable to improve the binding affinity, effector functions, half-life and / or other biological properties of the binding agent. Amino acid sequence modification / variants of the binding agents are generally prepared by introducing appropriate nucleotide changes into the encoding nucleic acid, or by peptide synthesis. All of the below described amino acid sequence modifications should result in a binding agent which still retains the desired biological activity (e.g., binding to one or more of activin A, activin B, GDF-8, GDF-11, without substantial binding to BMP-9 and BMP-10) of the unmodified parental molecule.

[0239] As used herein, the term “functionally equivalent” refers to modified sequences that have the same or substantially the same biological activity or function as the original sequence from which it is derived, e.g., no significant change in physiological, chemical, physico- chemical or functional properties compared to the original sequence. The term “substantially identical” refers to sequences that are functionally equivalent to the original or reference sequence and have a high degree of sequence identity thereto. Generally, a substantially identical sequence is at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% identical to the original or reference sequence and has the same function. In some cases when referring to nucleic acid sequences, a substantially identical sequence hybridizes to the original sequence under high stringency conditions, for example at salt and temperature conditions substantially equivalent to 0.5 X SSC to about 5 X SSC and 65oC for both hybridization and wash. In general, modified sequences that are substantially identical or functionally equivalent to sequences provided in accordance with the present disclosure are meant to be encompassed. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0240] Amino acid modifications include, for example, deletions from, and / or insertions into, and / or substitutions of, residues within the amino acid sequences of the binding agents. Any combination of deletion, insertion, and substitution is made to arrive at the final construct, provided that the final construct possesses the desired characteristics. The amino acid changes also may alter post-translational processes of the binding agents, such as changing the number or position of glycosylation sites. In a particular embodiment, one or more amino acid is changed to alter a glycosylation site.

[0241] For example, 1, 2, 3, 4, 5, or 6 amino acids may be inserted or deleted in a binding agent. Preferably, amino acid sequence insertions include amino- and / or carboxyl-terminal fusions ranging in length from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 residues to polypeptides containing a hundred or more residues, as well as intra-sequence insertions of single or multiple amino acid residues. An insertional variant of the polypeptides or binding agents of the disclosure includes fusion to the N-terminus or to the C-terminus of the polypeptides or binding agents of an enzyme or fusion to a polypeptide which increases the serum half-life of the binding agents.

[0242] It is envisioned that modifications of the binding agents described herein are also encompassed. Modifications encompassed by the present disclosure include those having a variation in the amino acid sequence of the polypeptides or binding agents. Modifications of the binding agents include, for example, those having similar or improved binding affinity, avidity, ligand specificity, potency of inhibition, stability, manufacturability, half-life, and / or reduced aggregation in comparison with the binding agents disclosed herein.

[0243] One site of interest for substitutional mutagenesis includes the Fc domain monomer, as described hereinabove. Exemplary embodiments of modified polypeptides or binding agents of the present disclosure may comprise those having a modified IgG1, IgG2, IgG3, or IgG4 constant region or a portion thereof. In an embodiment, the polypeptides or binding agents comprise an IgG1 constant region (modified or unmodified). In an embodiment, the polypeptides or binding agents comprise an IgG2 constant region (modified or unmodified). In an embodiment, the polypeptides or binding agents comprise an IgG3 constant region (modified or unmodified). In an embodiment, the polypeptides or binding agents comprise an IgG4 constant region (modified or unmodified).

[0244] Modifications encompassed by the present disclosure include those which may comprise an insertion, a deletion or an amino acid substitution (conservative or non- conservative). These modifications may have at least one amino acid residue in its amino acid Attorney Docket No.35PH-005 / 03WO 349552-2048 sequence removed and a different residue inserted in its place. It should be understood that variation may occur in multiple regions of the binding agents, as long as the desired binding or biological activity is maintained.

[0245] It is known in the art that modifications and variants may be generated by substitutional mutagenesis and retain the biological activity (i.e., functional equivalence) of the binding agents of the present disclosure. These modifications or variants have at least one amino acid residue in the amino acid sequence removed and a different residue inserted in its place, e.g., one or more conservative amino acid substitution. In general, a conservative amino acid substitution is the substitution of an amino acid residue for another amino acid residue with similar chemical properties (e.g., size, charge, or polarity).

[0246] Generally, the degree of similarity and identity between variant polypeptide chains is determined herein using the Blast2 sequence program (Tatusova, T.A. and Madden, T.L., 1999) using default settings, i.e., blastp program, BLOSUM62 matrix (open gap 11 and extension gap penalty 1; gapx dropoff 50, expect 10.0, word size 3) and activated filters.

[0247] However, the level of identity may also be determined over the entire length of a given sequence. Percent identity will therefore be indicative of amino acids which are identical in comparison with the original peptide and which may occupy the same or similar position. Percent similarity will be indicative of amino acids which are identical and those which are replaced with conservative amino acid substitution in comparison with the original peptide at the same or similar position.

[0248] In some embodiments, modifications of the binding agents of the present disclosure therefore comprise amino acid sequences which have at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with an original sequence or a portion of an original sequence.

[0249] In some embodiments, substitutions are conservative substitutions. However, any substitution (including non-conservative substitution) is envisaged as long as the binding agents retain their capability to bind and / or inhibit the desired TGFf superfamily ligands, without substantially binding or inhibiting BMP-9 and / or BMP-10.

[0250] Generally, the nucleic acid sequence homology, similarity, or identity between the nucleotide sequences encoding binding agents of the disclosure and the nucleotide sequences depicted herein are at least 60%, and more typically with preferably increasing homologies or Attorney Docket No.35PH-005 / 03WO 349552-2048 identities of at least 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, and almost 100%. GLP-1 Agonists

[0251] In some embodiments, the present disclosure provides combinations comprising a E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX GSJ G MQYIGMTS-like peptide 1 (GLP-1) agonist. Herein, the term “GLP-1 agonist” refers to a class of agents that binds to and activates the GLP-1 receptor. GLP-1 receptor agonists may also be referred to as “incretin mimetics” or “GLP-1 receptor agonists”.

[0252] The glucagon-like peptide-1 receptor is a pancreatic beta cell receptor that stimulates insulin secretion upon binding of the hormone glucagon-like peptide 1 (GLP-1). GLP-1 is a type of incretin hormone, all of which regulate insulin release in response to blood sugar. GLP- 1 agonists mimic the action of GLP-1 peptide and activate the GLP-1 receptor upon binding, stimulating insulin secretion. However, GLP-1 agonists exhibit significant side effects and tolerability issues at effective doses. GLP-1 agonists have also been shown to decrease lean mass of a subject during treatment. Warnings and precautions for GLP-1 agonists (e.g., semaglutide) include but are not limited to: thyroid C-cell tumors, acute pancreatitis, acute gallbladder disease, hypoglycemia, acute kidney injury, severe adverse gastrointestinal reactions, hypersensitivity, e.g., anaphylactic reactions and angioedema, diabetic retinopathy complications in subjects with Type 2 Diabetes, heart rate increase, and suicidal behavior and ideation. Adverse reactions reported in at least 5% of subjects treated with a GLP-1 agonist (e.g., semaglutide), include nausea, diarrhea, vomiting, constipation, abdominal pain, headache, fatigue, dyspepsia, dizziness, abdominal distension, eructation, hypoglycemia in patients with type 2 diabetes, flatulence, gastroenteritis, and gastroesophageal reflux disease. Thus, there is a need for optimized dosage and treatments with GLP-1 agonists.

[0253] As provided herein, the GLP-1 agonist of the disclosure may be a peptide, antibody, small molecule, or an aptamer. In some embodiments, the GLP-1 agonist is a peptide or peptide analog, including but not limited to: exenatide, exenatide extended-release, efpeglenatide, dulaglutide, liraglutide, lixisenatide, lotiglipron, semaglutide, tirzepatide, cotadutide, noiiglutide, oxyntomodulin, orforglipron, retatrutide, albiglutide, beinaglutide and PEG- loxenatide, pemvidutide, and danuglipron. In some embodiments, the GLP-1 agonist is a small molecule non-peptide agonist, e.g, danuglipron. In some embodiments, the GLP-1 agonist is Attorney Docket No.35PH-005 / 03WO 349552-2048 semaglutide. In some embodiments, the GLP-1 agonist is tirzepatide. In some embodiments, the GLP-1 agonist is retatrutide.

[0254] In some embodiments, the GLP-1 agonist is a dual agonist that binds and activates or deactivates a second receptor in addition to a GLP-1 receptor, wherein the second receptor is glucose-dependent insulinotropic (GIP) receptor or a glucagon (GCG) receptor. An exemplary dual acting GLP-1 agonist that binds both GLP-1 receptor and GIP receptor is tirzepatide. Exemplary dual acting GLP-1 agonists that binds both GLP-1 receptor and GCG receptor are cotadutide, noiiglutide, and oxyntomodulin, and are included in this disclosure as possible therapeutic agents to be used in combination with the E<;a WYUKVLGROQ] QOMGSJ HOSJOSM GMKSX. In some embodiments, the GLP-1 agonist is also a GIP antagonist. In some embodiments, the GLP-1 agonist is also a GCG antagonist. In some embodiments, the GLP-1 agonist is a triagonist of GIP / GLP-l / glucagon receptor, e.g., a GGG triagonist, e.g., LY343794.

[0255] In some embodiments, the GLP-1 agonist is GLP-1(7-37); GLP-1(7-36)-NH2; liraglutide; albiglutide; taspoglutide; dulaglutide; semaglutide; LY2428757; exendin-4; exendin-3; Leu14-exendin-4; Leu14,Phe25-exendin-4; Leu14,Ala19,Phe25-exendin-4; exendin- 4(1-30); Leu14-exendin-4(1-30); Leu14,Phe25-exendin-4(1-30); Leu14,Ala19,Phe25-exendin-4(1- 30); exendin-4(1-28); Leu14-exendin-4(1-28); Leu14,Phe25-exendin-4(1-28); Leu14,Ala19,Phe25- exendin-4(1-28); Leu14,Lys17,20,Ala19,Glu21,Phe5,Gln28-exendin-4; Leu14,Lys17,20,Ala19,Glu21,Gln28-exendin-4; octylGly14,Gln28-exendin-4; Leu14,Gln28,octylGly34-exendin-4; Phe4,Leu14,Gln28,Lys33,Glu34, Ile35,36,Ser37-exendin-4(1- 37); Phe4,Leu14,Lys17,20,35, Ala19,Glu21,Gln28-exendin-4; Val11,IIe13,Leu14,Ala16,Lys21,Phe25- exendin-4; exendin-4-Lys40; GLP-1(7-37); GLP-1(7-36)-NH2; Aib8,35,Arg26,34,Phe31-GLP-1(7- 36); Arg34-GLP-1(7-37); Glu30-GLP-1(7-37); Lys22-GLP-1(7-37); Gly8,36,Glu22-GLP-1(7-37); Val8,Glu22,Gly36-GLP-1(7-37), Gly8,36, Glu22,Lys33,Asn34-GLP-1(7-37); Val8,50, Glu22,Lys33, Asn34,Gly36-GLP-1(7-37);'Gly8,36,Glu22,Pro37-GLP-1(7-37); Val8, Glu22, Gly36,Pro37-GLP- 1(7-37);' Gly8,36,Glu22,Lys33, Asn34,Pro37-GLP-1(7-37); Val8,Glu22,Lys33,Asn34,Gly36,Pro37- GLP-1(7- 37); Gly8,36,Glu22-GLP-1(7-36); Val8,Glu22,Gly36-GLP-1(7-36); Val8,Glu22,Asn34,Gly36-GLP-1(7-36), Gly8,36,Glu22,Asn34-GLP-1(7-36); [W-(17- carboxyheptadecanoic acid)Lys20]exendin-4-NH2; [W-(17- carboxyheptadecanoyl)Lys32]exendin-4-NH2; [ desamino-His1,Ne-(17- carboxyheptadecanoyl)Lys20]exendin-4-NH2; [Arg12,27,NLe14,W-(17-carboxy- heptadecanoyl)Lys32]exendin-4-NH2; [W-(19-carboxy-nonadecanoylamino)Lys20]-exendin-4- NH2); [W-(15-carboxypentadecanoylamino)Lys20]-exendin-4-NH2;[W-(13- Attorney Docket No.35PH-005 / 03WO 349552-2048 carboxytridecanoylamino)Lys20]exendin-4-NH2; [W-(11-carboxy-undecanoyl-amino)Lys20]exendin-4-NH2; exendin-4-Lys40(e-MPA)-NH2; exendin-4-Lys40(e-AEEA-AEEA-MPA)- NH2; exendin-4-Lys40(e-AEEA-MPA)-NH2; exendin-4-Lys40(e-MPA)-albumin; exendin-4- Lys40(e-AEEA-AEEA-MPA)-albumin; exendin-4-Lys40(e-AEEA-MPA)-albumin; desamino- His7,Arg26,Lys34(W-(yGlu(N-a-hexadecanoyl)) )-GLP-1(7-37); desamino-His7,Arg26,Lys34(Ne-octanoyl)-GLP-1(7-37); Arg26,34,Lys38(Ne-(w-carboxypentadecoyl))-GLP-1 (7-38); Arg26,34,Lys36(N -(y-Glu(N-a-hexadecanoyl)))-GLP-1(7-36); [Aib8;Lys37]GLP-1_(7- 37); [Aib8, Lys26]GLP-1_(7-37); [Aib8,22;Lys36]GLP-1(7-36)-Amide; [Aib8,22, BLeu32, Lys36]GLP-1(7-36)-Amide; Aib8,22, Lys37]GLP-1(7-37)-Amide; [Aib8,22,BLeu32,Lys37]GLP- (7-37)-Amide; or a peptide having at least 80% sequence identity thereto. In some embodiments, the GLP-1 agonist is a peptide or analog thereof described in U.S. Patent No. 10,905,772, which is incorporated herein by reference in its entirety. Pharmaceutical compositions

[0256] In some embodiments, the individual components (e.g., the binding agents and GLP- 1 agonists) of the combinations provided herein are formulated in separate pharmaceutical compositions. In some embodiments, the individual components (e.g., the binding agents and GLP-1 agonists) of the combinations provided herein are formulated in the same pharmaceutical composition. The pharmaceutical composition generally comprises the binding agent disclosed herein and / or a GLP-1 agonist and a pharmaceutically acceptable carrier.

[0257] The preparation of pharmaceutical compositions can be carried out as known in the art (see, for example, Remington: The Science and Practice of Pharmacy, 20th Edition, 2000). For example, a therapeutic compound and / or composition, together with one or more solid or liquid pharmaceutical carrier substances and / or additives (or auxiliary substances) and, if desired, in combination with other pharmaceutically active compounds having therapeutic or prophylactic action, are brought into a suitable administration form or dosage form which can then be used as a pharmaceutical in human or veterinary medicine. Pharmaceutical preparations can also contain additives, of which many are known in the art, for example fillers, disintegrants, binders, lubricants, wetting agents, stabilizers, emulsifiers, dispersants, preservatives, sweeteners, colorants, flavorings, aromatizers, thickeners, diluents, buffer substances, solvents, solubilizers, agents for achieving a depot effect, salts for altering the osmotic pressure, coating agents or antioxidants. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0258] The term "pharmaceutical composition" means a composition comprising a binding agent and / or a GLP-1 agonist as described herein and at least one component comprising pharmaceutically acceptable carriers, diluents, adjuvants, excipients, or vehicles, such as preserving agents, fillers, disintegrating agents, wetting agents, emulsifying agents, suspending agents, sweetening agents, flavoring agents, perfuming agents, antibacterial agents, antifungal agents, lubricating agents and dispensing agents, depending on the nature of the mode of administration and dosage forms.

[0259] The term "pharmaceutically acceptable carrier" is used to mean any carrier, diluent, adjuvant, excipient, or vehicle, as described herein or as known in the art. Examples of suspending agents include ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth, or mixtures of these substances. Prevention of the action of microorganisms can be ensured by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, and the like. It may also be desirable to include isotonic agents, for example sugars, sodium chloride, and the like. Prolonged absorption of the injectable pharmaceutical form can be brought about by the use of agents delaying absorption, for example, aluminum monosterate and gelatin. Non-limiting examples of suitable carriers, diluents, solvents, or vehicles include water, salt solutions, phosphate buffered saline (PBS), gelatins, oils, alcohols, polyols, suitable mixtures thereof, vegetable oils (such as olive oil), and injectable organic esters such as ethyl oleate. Non-limiting examples of excipients include lactose, milk sugar, sodium citrate, calcium carbonate, and dicalcium phosphate. Non-limiting examples of disintegrating agents include starch, alginic acids, and certain complex silicates. Non-limiting examples of lubricants include magnesium stearate, sodium lauryl sulphate, talc, as well as high molecular weight polyethylene glycols.

[0260] The term "pharmaceutically acceptable" means it is, within the scope of sound medical judgment, suitable for use in contact with the cells of a subject, e.g., humans and animals, without undue toxicity, irritation, allergic response, and the like, and are commensurate with a reasonable benefit / risk ratio.

[0261] Supplementary active compounds can also be incorporated into the compositions. For example, a pharmaceutical composition provided herein may further comprise at least one additional therapeutic agent, as discussed further below. Attorney Docket No.35PH-005 / 03WO 349552-2048

[0262] The pharmaceutical compositions described herein may be administered by any number of routes including, but not limited to, oral, intravenous, intramuscular, intra-arterial, intramedullary, intrathecal, intraventricular, transdermal, subcutaneous, intraperitoneal, intranasal, enteral, topical, sublingual, or rectal means.

[0263] In some embodiments, a pharmaceutical composition provided herein can be administered orally, for example in the form of pills, tablets, lacquered tablets, sugar-coated tablets, granules, hard and soft gelatin capsules, aqueous, alcoholic or oily solutions, syrups, emulsions or suspensions, or rectally, for example in the form of suppositories.

[0264] In other embodiments, a pharmaceutical composition provided herein can be administered parenterally, for example subcutaneously, intramuscularly or intravenously in the form of solutions for injection or infusion. Other suitable administration forms are, for example, percutaneous or topical administration, for example in the form of ointments, creams, tinctures, sprays or transdermal therapeutic systems, or the inhalative administration in the form of nasal sprays or aerosol mixtures, or, for example, microcapsules, implants or wafers.

[0265] Pharmaceutical compositions typically must be sterile and stable under the conditions of manufacture and storage. A composition can be formulated as a solution, microemulsion, liposome, or other ordered structure suitable to high drug concentration. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as mannitol, sorbitol, or sodium chloride in the composition. Prolonged absorption of injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, monostearate salts and gelatin. Moreover, a compound can be administered in a time release formulation, for example in a composition which includes a slow release polymer. The compound can be prepared with carriers that will protect against rapid release, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, polylactic acid and polylactic, polyglycolic copolymers (PLG). Attorney Docket No.35PH-005 / 03WO 349552-2048

[0266] Many methods for the preparation of such formulations are generally known to those skilled in the art. Sterile injectable solutions can be prepared by incorporating an active compound, such as a binding agent provided herein, in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle that contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, common methods of preparation are vacuum drying and freeze-drying which yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof. Compounds may also be formulated with one or more additional compounds that enhance their solubility.

[0267] In some embodiments, a pharmaceutical composition of the disclosure comprises a sterile injectable solution. In some embodiments, the sterile injectable solution comprises a sterile powder which is reconstituted with an acceptable solution, e.g., water.

[0268] In some embodiments, the pharmaceutical compositions of the present disclosure comprises a binding agent and a GLP-1 agonist, NaPO4, glycine, and histidine at a pH of about 7.4-7.6. In some embodiments, the formulation does not comprise a surfactant (e.g., polysorbate 80).

[0269] In some embodiments, glycine is present at a concentration of about 10 mM to about 150 mM (e.g., 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, ...

Claims

Attorney Docket No.35PH-005 / 03WO 349552-2048 CLAIMS 1. A combination comprising (a) a TGFa superfamily ligand binding agent comprising a first polypeptide and a second polypeptide, wherein the first and second polypeptides each comprise: i. a polypeptide comprising an amino acid sequence that is at least 90% identical to an Activin receptor type IIB (ActRIIB) ectodomain (ECD) variant, the ActRIIB ECD variant comprising an amino acid substitution at the position corresponding to position 33 of SEQ ID NO: 2; ii. an Fc domain monomer; and iii. a peptide linker joining the polypeptide to the Fc domain monomer; and (b) a Glucagon-like peptide 1 (GLP-1) agonist.

2. The combination of claim 1, wherein the ActRIIB ECD variant demonstrates reduced inhibition of BMP-9 and / or BMP-10 compared to a wild-type ActRIIB ectodomain.

3. The combination of claim 1 or claim 2, wherein the amino acid substitution is selected from L33F, L33Q, L33Y, L33W, L33H, L33R, L33E, L33K, and L33M.

4. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33F.

5. The combination of claim 4, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 10; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

10.

6. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33Q.

7. The combination of claim 6, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 11; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

11.

8. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33Y.Attorney Docket No.35PH-005 / 03WO 349552-2048 9. The combination of claim 8, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 12; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

12.

10. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33W.

11. The combination of claim 10, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 13; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

13.

12. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33H.

13. The combination of claim 12, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 14; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

14.

14. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33R.

15. The combination of claim 14, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 15; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

15.

16. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33E.

17. The combination of claim 16, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 16; or (b) comprises or consists of the amino acid sequence of SEQ ID NO: 16.Attorney Docket No.35PH-005 / 03WO 349552-2048 18. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33K.

19. The combination of claim 18, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 17; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

17.

20. The combination of any one of claims 1-3, wherein the ActRIIB ECD variant comprises the amino acid substitution L33M.

21. The combination of claim 20, wherein the ActRIIB ECD variant (a) comprises an amino acid sequence that is at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 18; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

18.

22. The combination of claim 21, wherein the ActRIIB ECD variant further comprises an amino acid substitution at position 27 of SEQ ID NO:

2.

23. The combination of claim 21 or 22, wherein the ActRIIB ECD variant further comprises an amino acid substitution at position 69 of SEQ ID NO:

2.

24. The combination of any one of claims 22-23, wherein the ActRIIB ECD variant further comprises one or more amino acid substitutions which is G27D, G27E, T69E, T69Q, or T69H.

25. The combination of any one of claims 1-24, wherein the ActRIIB ECD variant further comprises one or more additional amino acids at the N or C terminus.

26. The combination of claim 25, wherein the ActRIIB ECD variant further comprises the following amino acids at the N terminus: GRGEA (SEQ ID NO: 63) and / or the following amino acids at the C-terminus: APT.

27. The combination of any one of claims 1-26, wherein the first and the second polypeptides comprise the following structure, from N- to C-terminus: ActRIIB-ECD – peptide linker – Fc domain monomer.Attorney Docket No.35PH-005 / 03WO 349552-2048 28. The combination of any one of claims 1-27, wherein the Fc domain monomer is an IgG1, IgG2, IgG3 or IgG4 isotype.

29. The combination of any one of claims 1-28, wherein the Fc domain monomer is a human Fc domain monomer or a murine Fc domain monomer.

30. The combination of any one of claims 1-29, wherein the Fc domain monomer is engineered to reduce aggregation or to modulate stability of a dimer of the polypeptide.

31. The combination of claim 30, wherein the Fc domain monomer comprises the amino acid substitutions of M252Y, S254T, and T256E (YTE).

32. The combination of claim 30, wherein the Fc domain monomer comprises the M252Y amino acid substitution.

33. The combination of any one of claims 28-32, wherein the Fc domain monomer includes a D at position 356 and an L at position 358 (DL).

34. The combination of any one of claims 28-32, wherein the Fc domain monomer includes an E at position 356 and an M at position 358 (EM).

35. The combination of any one of claims 28-34, wherein the Fc domain monomer further comprises a Lysine residue (K) at the C terminus.

36. The combination of any one of claims 1-35, wherein the Fc domain monomer (a) comprises an amino acid sequence that is at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to any one of SEQ ID NOs: 252-292; or (b) comprises or consists of an amino acid sequence selected from any one of SEQ ID NOs: 252-292.

37. The combination of any one of claims 28-36, wherein the Fc domain monomer is an IgG1 isotype 38. The combination of claim 37, wherein the Fc domain monomer comprises or consists of the amino acid sequence set forth in SEQ ID NO: 253, SEQ ID NO: 255, or SEQ ID NO: 256.Attorney Docket No.35PH-005 / 03WO 349552-2048 39. The combination of any one of claims 1-38, wherein the Fc domain monomer in the first polypeptide forms a dimer with the Fc domain monomer in the second polypeptide.

40. The combination of any one of claims 1-39, wherein the peptide linker is Glycine-rich.

41. The combination of any one of claims 1-40, wherein the peptide linker is between 10 and 40 amino acids long.

42. The combination of claim 41, wherein the linker is at least 10 amino acids long, at least 14 amino acids long, at least 19 amino acids long, or at least 39 amino acids long.

43. The combination of claim 42, wherein the linker is 10 amino acids long, 14 amino acids long, 19 amino acids long, or 39 amino acids long.

44. The combination of any one of claims 40-43, wherein the peptide linker comprises the amino acid sequence set forth in any one of SEQ ID NOs: 89, 94, or 98.

45. The combination of any one of claims 1-44, wherein the ActRIIB-ECD (a) comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to any one of SEQ ID NOs:4-62; or (b) comprises or consists of an amino acid sequence selected from any one of SEQ ID NOs: 4-62.

46. The combination of any one of claims 1-45, wherein the ActRIIB-ECD comprises or consists of the amino acid sequence of SEQ ID NO: 10-18, or a sequence at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto.

47. The combination of any one of claims 1-46, wherein the ActRIIB-ECD comprises or consists of the amino acid sequence of SEQ ID NO: 13 or a sequence at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical thereto.

48. The combination of any one of claims 1-47, wherein the first and / or second polypeptide: (a) comprise an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to an amino acid sequence selected from SEQ ID NOs: 174-251; orAttorney Docket No.35PH-005 / 03WO 349552-2048 (b) comprise or consist of an amino acid sequence selected from SEQ ID NOs: 174- 251.

49. The combination of any one of claims 1-48, wherein the first and / or second polypeptide: (a) comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to an amino acid sequence selected from SEQ ID NOs: 175, 176, 180, 204-214, and 230-234; or (b) comprises or consists of an amino acid sequence selected from SEQ ID NOs: 175, 176, 180, 204-214, and 230-234.

50. The combination of any one of claims 1-48, wherein the first and / or second polypeptide: (a) comprises an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical to an amino acid sequence selected from SEQ ID NOs: 211 and 230- 234; or (b) comprises or consists of an amino acid sequence selected from SEQ ID NOs: 211 and 230-234.

51. The combination of any one of claims 1-48, wherein the first and / or second polypeptide: (a) comprises or consists of the amino acid sequence of SEQ ID NO: 231, or an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical thereto; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

231.

52. The combination of any one of claims 1-48, wherein the first and / or second polypeptide (a) comprises or consists of the amino acid sequence of SEQ ID NO: 234, or an amino acid sequence that is at least 95%, 96%, 97%, 98%, or 99% identical thereto; or (b) comprises or consists of the amino acid sequence of SEQ ID NO:

234.

53. The combination of any one of claims 1-52, wherein the first and / or second polypeptide further comprise an albumin-binding domain, a fibronectin domain, or a human serum albumin domain fused to the N- or C-terminus of the ActRIIB-ECD via a linker.Attorney Docket No.35PH-005 / 03WO 349552-2048 54. The combination of any one of claims 1-53, wherein the first and / or second polypeptide further comprises a signal peptide of SEQ ID NO: 1 at the N-terminus of the ActRIIB-ECD.

55. The combination of claim 54, wherein the signal peptide is cleaved from the mature protein.

56. The combination of any one of claims 1-55, wherein the binding agent is conjugated with a targeting agent, a therapeutic moiety, a detectable moiety, or a diagnostic moiety.

57. The combination of claim 56, wherein the targeting agent, the therapeutic moiety, the detectable moiety, or the diagnostic moiety comprises an antibody or antigen binding fragment thereof, a binding agent having affinity for another member of the TGFa superfamily or for another therapeutic target, a radiotherapy agent, an imaging agent, a fluorescent moiety, a cytotoxic agent, an anti-mitotic drug, a nanoparticle-based carrier, a polymer-conjugated drug, a nanocarrier, an imaging agent, a stabilizing agent, a drug, a nanocarrier, or a dendrimer.

58. The combination of any one of claims 1-57, wherein the first and second polypeptides form a dimer linked by at least one disulfide bond between the Fc domain monomer of the first polypeptide and the Fc domain monomer of the second polypeptide.

59. The combination of any one of claims 1-58, wherein the binding agent: (a) demonstrates similar or increased binding to human activin A, activin B, GDF- 8, and / or GDF-11 and demonstrates reduced binding to human BMP-9 and / or BMP-10 compared to a polypeptide comprising a WT ActRIIB-ECD; (b) does not substantially bind to human BMP-9; (c) demonstrates reduced binding to human BMP-10 compared to a polypeptide comprising a WT ActRIIB-ECD; (d) inhibits signaling of one or more of human activin A, activin B, GDF-8, and GDF-11; and / or (e) does not substantially inhibit human BMP-9 and / or BMP-10 signaling.

60. The combination of any one of claims 1-59, wherein the GLP-1 agonist is an antibody, small molecule, peptide, or aptamer.

61. The combination of any one of claims 1-60, wherein the GLP-1 agonist is selected from the group consisting of exenatide, exenatide extended-release, efpeglenatide, dulaglutide,Attorney Docket No.35PH-005 / 03WO 349552-2048 liraglutide, lixisenatide, lotiglipron, semaglutide, tirzepatide, cotadutide, noiiglutide, oxyntomodulin, orforglipron, retatrutide, albiglutide, beinaglutide and PEG-loxenatide, pemvidutide, and danuglipron.

62. The combination of any one of claims 1-59, wherein the GLP-1 agonist is selected from semaglutide and tirzepatide.

63. The combination of any one of claims 1-59, wherein the GLP-1 agonist is a dual GLP- 1 agonist and GIP agonist, a dual GLP-1 agonist and GCG agonist, or a triagonist of GIP / GLP- 1 / glucagon receptors.

64. The combination of any one of claims 1-63, wherein the binding agent and GLP-1 agonist are formulated in separate pharmaceutical compositions.

65. The combination of any one of claims 1-63, wherein the binding agent and GLP-1 agonist are formulated in the same pharmaceutical composition.

66. The combination of any one of claims 64-65, wherein the pharmaceutical composition is formulated for administration by injection or infusion.

67. The combination of claim 66, wherein the composition is formulated for intravenous, subcutaneous, intraperitoneal, or intramuscular administration.

68. A kit comprising the combination of any one of claims 1-67, and optionally, directions for use.

69. A method of treating or preventing a metabolic disease or condition in a subject in need thereof, the method comprising administering the combination of any one of claims 1-67 to the subject.

70. The method of claim 69, wherein the subject is a human.

71. The method of claim 69 or 70, wherein the metabolic disorder is selected from the group consisting of obesity, diabetes, metabolic syndrome, anti-psychotic drug-associated obesity, glucocorticoid-induced obesity, hypothalamic obesity associated with craniopharyngioma, Prader-Willi syndrome, and a monogenetic disorder associated with obesity such as Bardet- Biedl syndrome.Attorney Docket No.35PH-005 / 03WO 349552-2048 72. The method of claim 69 or 70, wherein the metabolic disorder is selected from obesity, Type 2 diabetes, and pre-diabetes.

73. The method of claim 71, wherein the metabolic disorder is obesity.

74. The method of any one of claims 69-73, wherein the method does not: cause a vascular complication in a subject; increase vascular permeability or leakage in a subject; increase red blood cell mass; increase hemoglobin; cause thrombocytopenia; cause a hematological complication in a subject; and / or does not cause a reduction in lean muscle mass in the subject.

75. The method of any one of claims 69-74, wherein the treatment increases lean mass in the subject.

76. The method of any one of claims 69-75, wherein the treatment reduces fat mass in the subject.

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