Factor VII conjugates
The present invention relates to the conjugation of Factor VII polypeptides with heparosan polymers. The resultant conjugates may be used to deliver Factor VII, for example in the treatment or prevention of bleeding disorders.
1. A conjugate comprising a Factor VII polypeptide and a heparosan polymer;
wherein said heparosan polymer has a size in a range selected from the group consisting of 30-50kDa, 35-65kDa, 35-45kDa, 45-55kDa, 40-60kDa and 55-65kDa; and
wherein said conjugate exhibits at least about 20% more Factor X activation activity in comparison to a conjugate comprising a Factor VII polypeptide and a polyethylene glycol polymer of about the same size.
2. The conjugate according to claim 1 , wherein said heparosan polymer has a molecular weight selected from the group consisting of 38kDa, 39kDa, 40kDa, 41kDa, and 42kDa.
3. The conjugate according to claim 1 , wherein said heparosan polymer has a polydispersity index (Mw/Mn) of less than 1.10, 1.09, 1.08, 1.07, 1.06, 1.05, 1.04 or 1.03.
4. The conjugate according to claim 1 , wherein the heparosan polymer is attached to the Factor VII polypeptide via an N-glycan.
5. The conjugate according to claim 1 , wherein said Factor VII polypeptide is a mutant Factor VII polypeptide carrying a free cysteine, and wherein said heparosan polymer is attached to said cysteine.
6. The conjugate according to claim 1 , wherein said conjugate has
(a) increased circulating half-life compared to the same Factor VII polypeptide which is not conjugated to a heparosan polymer;
(b) increased functional half-life compared to the same Factor VII polypeptide which is not conjugated to a heparosan polymer;
(c) increased mean residence time compared to the same Factor VII polypeptide which is not conjugated to a heparosan polymer; and/or
(d) increased functional mean residence time compared to the same Factor VII polypeptide which is not conjugated to a heparosan polymer.
7. The conjugate according to claim 1 , wherein said Factor VII polypeptide is a Factor VIIa polypeptide.
8. The conjugate according to claim 1 , wherein the amino acid sequence of the Factor VII polypeptide differs from the sequence of wild-type Factor VII by insertion, deletion, and/or substitution of one or more amino acids.
9. The conjugate according to claim 8 , wherein the amino acid sequence of the Factor VII polypeptide differs from the sequence of wild-type Factor VII by one, two or three amino acids substitutions.
10. The conjugate according to claim 1 , wherein said Factor VII polypeptide is human wild-type Factor VIIa.
11. A method for preparing a conjugate according to claim 1 , comprising covalently binding a heparosan polymer to an isolated Factor VII polypeptide.
12. A pharmaceutical composition comprising the conjugate according to claim 1 and a pharmaceutically acceptable carrier or diluent.
13. A method for treating or preventing a bleeding disorder, comprising administering the conjugate according to claim 1 to a subject in need thereof.
14. A method for treating or preventing a bleeding disorder, comprising administering the pharmaceutical composition according to claim 12 to a subject in need thereof.