Antibodies for binding plasmin

1 . An antigen binding protein comprising an antigen binding domain that binds to the serine protease domain of plasmin, wherein the antigen binding domain comprises:

(a) a VH comprising a CDR1 comprising the sequence set forth in SEQ ID NO: 4, a CDR2 comprising the sequence set forth between in SEQ ID NO: 5 and a CDR3 comprising the sequence set forth in SEQ ID NO: 6, and

(b) a VL comprising a CDR1 comprising the sequence set forth in SEQ ID NO: 1, a CDR2 comprising the sequence set forth in SEQ ID NO: 2 and a CDR3 comprising the sequence set forth in SEQ ID NO: 3.

2 . The antigen binding protein of claim 1 , wherein the protein further comprises at least one of:

(i) a VH comprising a framework region (FR) 1 comprising a sequence at least about 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 97%, at least 99% identical to the sequence set forth in SEQ ID NO: 21, a FR2 comprising a sequence at least about 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 97%, at least 99% identical to the sequence set forth in SEQ ID NO: 22, a FR3 comprising a sequence at least about 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 97%, at least 99% identical to the sequence set forth in SEQ ID NO: 23, and a FR4 comprising a sequence at least about 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 97%, at least 99% identical to the sequence set forth in SEQ ID NO: 24;

(ii) a VL comprising a FR 1 comprising a sequence at least about 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 97%, at least 99% identical to the sequence set forth in SEQ ID NO: 17, a FR2 comprising a sequence at least about 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 97%, at least 99% identical to the sequence set forth in SEQ ID NO: 18, a FR3 comprising a sequence at least about 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 97%, at least 99% identical to the sequence set forth in SEQ ID NO: 19, and a FR4 comprising a sequence at least about 80%, at least 85%, at least 90%, at least 92%, at least 95%, at least 97%, at least 99% identical to the sequence set forth in SEQ ID NO: 20;

(iii) a VH comprising a FR1 comprising the sequence set forth in SEQ ID NO: 21, a FR2 comprising the sequence set forth between in SEQ ID NO: 22, a FR3 comprising the sequence set forth in SEQ ID NO: 23, and a FR4 comprising the sequence set forth in SEQ ID NO: 24;

(iv) a VL comprising a FR1 comprising the sequence set forth in SEQ ID NO: 17, a FR2 comprising the sequence set forth between in SEQ ID NO: 18, a FR3 comprising the sequence set forth in SEQ ID NO: 19, and a FR4 comprising the sequence set forth in SEQ ID NO: 20; or

(v) a VH comprising a FR1 comprising the sequence set forth in SEQ ID NO: 21, a FR2 comprising the sequence set forth between in SEQ ID NO: 22, a FR3 comprising the sequence set forth in SEQ ID NO: 23, and a FR4 comprising the sequence set forth in SEQ ID NO: 24; and a VL comprising a FR1 comprising the sequence set forth in SEQ ID NO: 17, a FR2 comprising the sequence set forth between in SEQ ID NO: 18, a FR3 comprising the sequence set forth in SEQ ID NO: 19, and a FR4 comprising the sequence set forth in SEQ ID NO: 20.

3 . The antigen binding protein of claim 1 , wherein the antigen binding protein is in the form of:

(i) a single chain Fv fragment (scFv);

(ii) a dimeric scFv (di-scFv);

(iii) one of (i) or (ii) linked to a constant region of an antibody, Fc or a heavy chain constant domain (CH) 2 and/or CH3;

(iv) one of (i) or (ii) linked to a protein that binds to an immune effector cell;

(v) an antibody;

(vi) a diabody;

(vii) a triabody;

(viii) a tetrabody;

(ix) a Fab;

(x) a F (ab')2;

(xi) a Fv;

(xii) a bispecific antibody;

(xiii) one of (vi) to (xii) linked to a constant region of an antibody, Fc or a heavy chain constant domain (CH) 2 and/or CH3; or

(xiv) one of (vi) to (xiii) linked to a protein that binds to an immune effector cell.

4 . The antigen binding protein of claim 1 , wherein the VH and VL are joined by a linker, wherein the linker is a chemical, one or more amino acids, or a disulphide bond formed between two cysteine residues.

5 . The antigen binding protein of claim 1 , wherein the protein is in the form of a fusion protein comprising an antigen binding protein of claim 1 .

6 . A conjugate comprising an antigen binding protein of claim 1 , conjugated to a label or a cytotoxic agent.

7 . A pharmaceutical composition comprising an antigen binding protein of claim 1 , or a fusion protein or conjugate thereof, and a pharmaceutically acceptable excipient.

8 . The antigen binding protein of claim 1 , wherein the antigen binding domain comprises a VH comprising a sequence at least about 95% or 96% or 97% or 98% or 99% identical to the sequence set forth in SEQ ID NO: 8.

9 . The antigen binding protein of claim 1 , wherein the antigen binding domain comprises a VH comprising the sequence set forth in SEQ ID NO: 8.

10 . The antigen binding protein of claim 1 , wherein the antigen binding domain comprises a VL comprising a sequence at least about 95% or 96% or 97% or 98% or 99% identical to the sequence set forth in SEQ ID NO: 7.

11 . The antigen binding protein of claim 1 , wherein the antigen binding domain comprises a VL comprising the sequence set forth in SEQ ID NO: 7.

12 . The antigen binding protein of claim 1 , wherein the antigen binding domain comprises a VH comprising the sequence set forth in SEQ ID NO: 8 and a VL comprising the sequence set forth in SEQ ID NO: 7.

13 . The antigen binding protein of claim 3 , wherein the antigen binding protein is in the form of a monoclonal antibody.