ALK4:ActRIIB heteromultimers and uses thereof
In certain aspects, the disclosure provides soluble heteromeric polypeptide complexes comprising an extracellular domain of an ALK4 receptor and an extracellular domain of ActRIIB In certain aspects, such soluble ALK4:ActRIIB complexes may be used to regulate (promote or inhibit) growth of tissues or cells including, for example, muscle, bone, cartilage, fat, neural tissue, tumors, and/or cancerous cells. In certain aspects, such ALK4:ActRIIB complexes are can be used to improve muscle formation, bone formation, metabolic parameters, and disorders associated with these tissues, cellular networks, kidney, and endocrine systems.
1. A method for treating a patient having a disorder associated with muscle loss or insufficient muscle growth, comprising administering to a patient in need thereof an effective amount of a soluble recombinant heteromultimer comprising an ALK4 polypeptide and an ActRIIB polypeptide, wherein the ALK4 polypeptide comprises an amino acid sequence that is at least 90% identical to amino acids 34-101 of SEQ ID NO: 9, and wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 90% identical to amino acids 29-109 of SEQ ID NO: 1, wherein the ActRIIB polypeptide does not comprise an aspartic acid (D) at the amino acid position corresponding to L79 of SEQ ID NO: 1; wherein the ALK4 and/or ActRIIB polypeptide is a fusion protein further comprising a heterologous domain, and wherein the heteromultimer binds to activin B; and wherein the disorder is muscle atrophy, muscular dystrophy, amyotrophic lateral sclerosis, or cachexia associated with cancer or cancer therapy.
2. The method of claim 1 , wherein the patient has muscle atrophy.
3. The method of claim 1 , wherein the patient has a muscular dystrophy.
4. The method of claim 3 , wherein the muscular dystrophy is Duchenne muscular dystrophy.
5. The method of claim 3 , wherein the muscular dystrophy is facioscapulohumeral muscular dystrophy.
6. The method of claim 3 , wherein the muscular dystrophy is any one of Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy (LGMD), myotonic dystrophy (MMD), oculopharyngeal muscular dystrophy (OPMD), distal muscular dystrophy (DD), or congenital muscular dystrophy (CMD).
7. The method of claim 1 , wherein the patient has amyotrophic lateral sclerosis.
8. The method of claim 1 , wherein the disorder is cachexia associated with cancer or cancer therapy.
9. The method of claim 1 , wherein the ALK4 polypeptide comprises an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to a polypeptide that:
a) begins at any one of amino acids 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, or 34 of SEQ ID NO: 9, and
b) ends at any one of amino acids 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, or 126 of SEQ ID NO: 9.
10. The method of claim 1 , wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to a polypeptide that:
a) begins at any one of amino acids 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29 of SEQ ID NO: 1, and
b) ends at any one of amino acids 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, or 134 of SEQ ID NO: 1.
11. The method of claim 1 , wherein the heterologous domain comprises an Fc immunoglobulin domain.
12. The method of claim 11 , wherein the Fc immunoglobulin domain comprises one or more amino acid modifications that promote heterodimer formation.
13. The method of claim 11 , wherein the immunoglobulin Fc domain comprises one or more amino acid modifications that inhibit homodimer formation.
14. The method of claim 11 , wherein the heterologous domain comprises an Fc immunoglobulin domain of IgG1 immunoglobulin.
15. The method of claim 1 , wherein the fusion protein further comprises a linker domain positioned between the ALK4 domain and the heterologous domain and/or a linker domain positioned between the ActRIIB domain and the heterologous domain.
16. The method of claim 1 , wherein the ALK4 polypeptide and/or ActRIIB polypeptide comprises one or more modified amino acid residues selected from the group consisting of: a glycosylated amino acid, a PEGylated amino acid, a farnesylated amino acid, an acetylated amino acid, a biotinylated amino acid, and an amino acid conjugated to a lipid moiety.
17. The method of claim 1 , wherein the ALK4 polypeptide and/or ActRIIB polypeptide is glycosylated and has a glycosylation pattern obtainable from a Chinese hamster ovary cell line.
18. The method of claim 1 , wherein the heteromultimer is an ALK4: ActRIIB heterodimer.
19. The method of claim 1 , wherein the ALK4 polypeptide comprises an amino acid sequence that is at least 95% identical to amino acids 34-101 of SEQ ID NO: 9, and wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 95% identical to amino acids 29-109 of SEQ ID NO: 1.
20. The method of claim 19 , wherein the heterologous domain comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
21. The method of claim 19 , wherein the fusion protein further comprises a linker domain positioned between the ALK4 domain and the heterologous domain and/or a linker domain positioned between the ActRIIB domain and the heterologous domain.
22. The method of claim 1 , wherein the ALK4 polypeptide comprises the amino acid sequence corresponding to amino acids 34-101 of SEQ ID NO: 9, and wherein the ActRIIB polypeptide comprises the amino acid sequence corresponding to amino acids 29-109 of SEQ ID NO: 1.
23. The method of claim 22 , wherein the heterologous domain comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
24. The method of claim 22 , wherein the fusion protein further comprises a linker domain positioned between the ALK4 domain and the heterologous domain and/or a linker domain positioned between the ActRIIB domain and the heterologous domain.
25. The method of claim 1 , wherein the ALK4 polypeptide comprises an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 10, and wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 2.
26. The method of claim 25 , wherein the heterologous domain comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
27. The method of claim 25 , wherein the fusion protein further comprises a linker domain positioned between the ALK4 domain and the heterologous domain and/or a linker domain positioned between the ActRIIB domain and the heterologous domain.
28. The method of claim 1 , wherein the ALK4 polypeptide comprises the amino acid sequence of SEQ ID NO: 10, and wherein the ActRIIB polypeptide comprises the amino acid sequence of SEQ ID NO: 2.
29. The method of claim 28 , wherein the heterologous domain comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
30. The method of claim 28 , wherein the fusion protein further comprises a linker domain positioned between the ALK4 domain and the heterologous domain and/or a linker domain positioned between the ActRIIB domain and the heterologous domain.
31. The method of claim 1 , wherein the ALK4 polypeptide comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 10, and wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 2.
32. The method of claim 31 , wherein the heterologous domain comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
33. The method of claim 31 , wherein the fusion protein further comprises a linker domain positioned between the ALK4 domain and the heterologous domain and/or a linker domain positioned between the ActRIIB domain and the heterologous domain.