Methods of identifying ActRIIB variants

• US 10,377,996 B2
• Filed: 10/27/2016
• Issued: 08/13/2019
• Est. Priority Date: 08/14/2008
• Status: Active Grant

• Current Assignee: Acceleron Pharma Inc. (Merck & Co., Inc.)
• Original Assignee: Acceleron Pharma Inc. (Merck & Co., Inc.)
• Inventors: Seehra, Jasbir, Pearsall, Robert Scott, Kumar, Ravindra
• Primary Examiner(s): Chandra, Gyan
• Application Number:
  US15/336,363
• Publication Number:
  US 20170204382A1
• Time in Patent Office: 1,020 Days
• CPC Class Codes: A61K 38/179 for growth factors; for growth regulators
• CPC Class Codes: A61K 38/1796 for hormones for neuromediators A61K38/1787
• CPC Class Codes: A61P 13/12 of the kidneys
• CPC Class Codes: A61P 21/00 Drugs for disorders of the muscular or neuromuscular system
• CPC Class Codes: A61P 7/00 Drugs for disorders of the blood or the extracellular fluid
• CPC Class Codes: A61P 7/02 Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors
• CPC Class Codes: A61P 7/06 Antianaemics
• CPC Class Codes: C07K 14/47 from mammals
• CPC Class Codes: C07K 14/475 Growth factors; Growth regulators
• CPC Class Codes: C07K 14/71 for growth factors; for growth regulators
• CPC Class Codes: C07K 2319/30 Non-immunoglobulin-derived peptide or protein having an immunoglobulin constant or Fc region, or a fragment thereof, attached thereto
• CPC Class Codes: C12N 9/12 transferring phosphorus containing groups, e.g. kinases (2.7)
• CPC Class Codes: C12Q 1/6897 involving reporter genes operably linked to promoters
• CPC Class Codes: C12Y 207/1103 Receptor protein serine/threonine kinase (2.7.11.30)

Abstract

In certain aspects, the present invention provides compositions and methods for increasing red blood cell and/or hemoglobin levels in vertebrates, including rodents and primates, and particularly in humans.

Claims

1. A method of identifying ActRIIB variants capable of increasing red blood cell or hemoglobin levels, comprising:

a) testing whether an ActRIIB variant specifically inhibits or reduces binding of an ActRIIB control polypeptide to an ActRIIB ligand;

wherein the ActRIIB ligand is one or more of myostatin and/or GDF11;

b) wherein if the ActRIIB variant inhibits or reduces binding of the ActRIIB control polypeptide to myostatin and/or GDF11, the method further comprises the step of administering the ActRIIB variant to a subject;

c) measuring the levels of red blood cell count and/or hemoglobin levels in the subject;

wherein if the ActRIIB variant increases red blood cell count and/or hemoglobin levels in the subject, an ActRIIB variant that is capable of increasing red blood cell or hemoglobin levels is identified;

wherein the ActRIIB variant comprises an amino acid sequence that is at least 80% identical to the sequence of amino acids 29-109 of SEQ ID NO;

1, and wherein the polypeptide comprises an acidic amino acid at the position corresponding to position 79 of SEQ ID NO;

1.

2. The method of claim 1, wherein the ActRIIB ligand is myostatin.

3. The method of claim 1, wherein the ActRIIB ligand is GDF11.

4. The method of claim 1, wherein the ActRIIB variant comprises an amino acid sequence that is at least 90% identical to the sequence of amino acids 29-109 of SEQ ID NO:

1, and wherein the polypeptide comprises an acidic amino acid at the position corresponding to position 79 of SEQ ID NO;

1.

5. The method of claim 1, wherein the ActRIIB variant comprises an amino acid sequence that is at least 95% identical to the sequence of amino acids 29-109 of SEQ ID NO:

1, and wherein the polypeptide comprises an acidic amino acid at the position corresponding to position 79 of SEQ ID NO;

1.

6. The method of claim 1, wherein the ActRIIB variant further comprises a constant domain of an immunoglobulin.

7. The method of claim 1, wherein the ActRIIB variant further comprises an Fc domain.

8. The method of claim 1, wherein the acidic amino acid is a glutamic acid.

9. The method of claim 1, wherein the acidic amino acid is an aspartic acid.

10. The method of claim 1, wherein the control ActRIIB polypeptide comprises an amino acid sequence that is at least 90% identical to the amino acids 29-109 of SEQ ID NO:

1.

11. The method of claim 1, wherein the control ActRIIB polypeptide comprises the amino acid sequence of amino acids 29-109 of SEQ ID NO:

1.