Chemically modified novel erythropoietin stimulating protein compositions and methods

Abstract

The present invention broadly relates to the field of protein modification, and, more specifically, the attachment of water soluble polymers to novel erythropoietin stimulating protein (NESP).

1 - 8 . (canceled)  
     
     
         9 . A pharmaceutical composition comprising: 
 (a) a substantially homogenous preparation of mono-PEGylated NESP, said mono-PEGylated NESP consisting of a polyethylene glycol moiety connected to a NESP moiety solely at the N-terminus thereof;    (b) fewer than 5% non-pegylated NESP molecules; and    (c) a pharmaceutically acceptable diluent, adjuvant or carrier.    
     
     
         10 - 13 . (canceled)  
     
     
         14 . A method of preparing a pegylated chemically modified hyperglycosylated Novel Erythropoietin Stimulating Protein (NESP) comprising the steps of (a) reacting NESP with polyethylene glycol under conditions whereby NESP becomes attached to one or more polyethylene groups, and (b) obtaining the reaction product(s).  
     
     
         15 . The method of claim  2  wherein said NESP is attached to polyethylene glycol under conditions for reductive alkylation.  
     
     
         16 . The method of claim  2  wherein said NESP is attached to polyethylene glycol under conditions for acylation.  
     
     
         17 . The method of claim  2  wherein said NESP is attached to polyethylene glycol under conditions for oxidation and then reduction of the product formed from oxidation.  
     
     
         18 . A method of producing a preparation of pegylated chemically modified hyperglycosylated Novel Erythropoietin Stimulating Protein wherein said method selectively attaches polyethylene glycol to the N-terminal of said protein.  
     
     
         19 . The preparation of claim  6  wherein said preparation comprises about 80% of the pegylated chemically modified hyperglycosylated novel erythropoietin stimulating protein is mono-pegylated.