Design and development of masked therapeutic antibodies to limit off-target effects

Abstract

In one embodiment, a masked monoclonal antibody (mAb) is provided, the mAb, encoded by a nucleic acid sequence or an amino acid sequence molecule comprising a signal sequence, a masking epitope sequence, a linker sequence that is cleavable by a protease specific to a target tissue; and an antibody or a functional fragment thereof. In another embodiment, a masked monoclonal antibody (mAb) is provided, which includes a therapeutic mAb and a mask, the mask comprising protein A and protein L attached by a protease cleavable linker.

1 .- 17 . (canceled) 
     
     
         18 . A method of treating cancer in a subject in need thereof, said method comprising administering to said subject a therapeutically effective amount of a mask molecule said mask molecule comprising:
 (i) domain IV of a HER2 receptor capable of binding to trastuzumab monoclonal antibody (mAb) or an antigen-binding fragment thereof and   (ii) an Fc portion of an IgG1 molecule connected to said domain IV by a matrix metalloproteinase-9 (MMP-9) protease-specific linker.   
     
     
         19 . The method of  claim 18 , wherein said MMP-9 protease is specific to a target tissue. 
     
     
         20 . The method of  claim 19 , wherein said target tissue is breast cancer tissue. 
     
     
         21 . The method of  claim 18 , wherein said linker comprises the sequence of SEQ ID NO: 3. 
     
     
         22 . The method of  claim 18 , wherein said linker has the sequence of SEQ ID NO:7. 
     
     
         23 . The method of  claim 18 , wherein said linker has the sequence of SEQ ID NO:4. 
     
     
         24 . The method of  claim 18 , wherein said mask is bound to trastuzumab mAb or said antigen-binding fragment thereof to form a masked trastuzumab or antigen-binding fragment thereof. 
     
     
         25 . The method of  claim 18 , said method further comprising administering trastuzumab. 
     
     
         26 . The method of  claim 18 , wherein said cancer is a HER2-expressing cancer. 
     
     
         27 . The method of  claim 18 , wherein said cancer is breast cancer.