Antidotes for factor xa inhibitors and methods of using the same

Abstract

The present invention relates antidotes to anticoagulants targeting factor Xa. The antidotes are factor X and factor Xa protein derivatives that bind to the factor Xa inhibitors thereby substantially neutralizing them but do not assemble into the prothrombinase complex. The derivatives describe herein lack or have reduced intrinsic coagulant activity. Disclosed herein are methods of reversing anticoagulation, stopping or preventing bleeding in a patient that is currently undergoing anticoagulant therapy with a factor Xa inhibitor.

1 . An isolated polypeptide factor X derivative comprising:
 1) a modified active site, and   2) a modified Gla domain or a deleted Gla domain;   wherein the derivative binds to a factor Xa inhibitor and does not assemble into a prothrombinase complex.   
     
     
         2 . The derivative of  claim 1 , further comprising a deletion of all or part of an activation peptide at an N-terminus of a heavy chain. 
     
     
         3 . The derivative of  claim 2 , wherein the deletion of all of part of the activation peptide comprises a deletion of amino acid residues 143 to 194 of SEQ ID No. 3 or an equivalent thereof. 
     
     
         4 . The derivative of  claim 1 , further comprising one or more amino acid modification, which modification prevents cleavage of a β-peptide. 
     
     
         5 . The derivative of  claim 4 , wherein the modification comprises deletion, substitution, or insertion at the amino acid. 
     
     
         6 . The derivative of  claim 4 , wherein the one or more modification comprises substitution of one or more amino acid residue selected from the group consisting of Arg429 or Ser436. 
     
     
         7 . The derivative of  claim 6 , wherein the one or more modification comprises at least Arg429Gln substitution. 
     
     
         8 . The derivative of  claim 7 , further comprising a Thr443Ala substitution. 
     
     
         9 . The derivative of  claim 1 , further comprising a deletion of a β-peptide. 
     
     
         10 . The derivative of  claim 9 , wherein the deletion of the β-peptide comprises a deletion of at least amino acid residues 430 to 448 of SEQ ID NO. 3 or an equivalent thereof. 
     
     
         11 . The derivative of  claim 1 , further comprising a modification at an EGF domain. 
     
     
         12 . The derivative of  claim 11 , wherein the modification is selected from the group consisting of a deletion of substantially all of an EGF1 domain, a deletion of substantially all of an EGF2 domain, and combinations thereof. 
     
     
         13 . The derivative of  claim 12 , wherein the deletion of substantially all of the EGF1 domain comprises at least about 50% of amino acid residues 46 to 84 of SEQ ID NO. 3 or an equivalent thereof. 
     
     
         14 . The derivative of  claim 12 , wherein the deletion of substantially all of the EGF1 domain comprises at least about 80% of amino acid residues 46 to 84 of SEQ ID NO. 3 or an equivalent thereof. 
     
     
         15 . The derivative of  claim 12 , wherein the deletion of substantially all of the EGF2 domain comprises at least about 50% of amino acid residues 85 to 128 of SEQ ID NO. 3 or an equivalent thereof. 
     
     
         16 . The derivative of  claim 12 , wherein the deletion of substantially all of the EGF2 domain comprises at least about 80% of amino acid residues 85 to 128 of SEQ ID NO. 3 or an equivalent thereof. 
     
     
         17 . The derivative of  claim 1 , wherein the derivative is expressed with a signal peptide. 
     
     
         18 . The derivative of  claim 17 , wherein the signal peptide is selected from the group consisting of a factor X signal peptide, a transferrin signal peptide, and a prothrombin signal peptide. 
     
     
         19 . The derivative of  claim 18 , wherein the transferrin signal peptide comprises amino acid residues SP1 to SP19 of SEQ ID NO. 27 or a peptide that is at least 80% homologous to amino acid residues SP1 to SP19 of SEQ ID NO. 27. 
     
     
         20 . The derivative of  claim 18 , wherein the prothrombin signal peptide comprises amino acid residues SP1 to SP24 of SEQ ID NO. 26 or a peptide that is at least 80% homologous to amino acid residues SP1 to SP24 of SEQ ID NO. 26. 
     
     
         21 .- 56 . (canceled)