Enhanced therapeutic usage of a purine nucleoside phosphorylase or nucleoside hydrolase prodrug

Abstract

The use of a purine nucleoside phosphorylase or nucleoside hydrolase or a vector encoding expression of one of these enzymes is detailed along with the use of a prodrug cleaved by the purine nucleoside phosphorylase or nucleoside hydrolase for the preparation of a direct injection inhibition of replicating or non-replicating targeted cells. The targeted cells do not normally express the introduced purine nucleoside phosphorylase or nucleoside hydrolase. The enzyme and prodrug are amenable to intermixing and injection as a single dose or as separate injection or administration to the targeted cells. The substance and prodrug efficacy are enhanced through exposure of the targeted cells to X-ray radiation. Administration of a prodrug regardless of administration route to the targeted cells is effective in combination with X-ray radiation therapy to kill or inhibit function of the targeted cells.

1 . A process of killing targeted cells in a solid tumor comprising:
 delivering a purine nucleoside phosphorylase or nucleoside hydrolase or a vector encoding expression thereof directly into proximity to the targeted cells; and   injecting intratumorally a prodrug cleaved by said purine nucleoside phosphorylase or nucleoside hydrolase directly into proximity to the targeted cells to release a purine base cytotoxic to the targeted cells so as to kill the targeted cells.   
     
     
         2 . The process of  claim 1  wherein said purine nucleoside phosphorylase or nucleoside hydrolase is delivered with a viral vector containing a nucleic acid encoding said purine nucleoside phosphorylase. 
     
     
         3 . The process of  claim 2  wherein said viral vector is an adenoviral vector. 
     
     
         4 . The process of  claim 1  wherein said purine nucleoside phosphorylase is present and is a mutant of  E. coli.    
     
     
         5 . The process of  claim 1  wherein said purine nucleoside phosphorylase is present and is a tailed mutant. 
     
     
         6 . The process of  claim 1  further comprising inhibiting growth of bystander cells to the targeted cells. 
     
     
         7 . The process of  claim 1  further comprising exposing the targeted cells to X-ray radiation. 
     
     
         8 . The process of  claim 1  wherein said purine nucleoside phosphorylase is present and said prodrug is fludarabine phosphate. 
     
     
         9 . The process of  claim 1  further comprising a sustained release carrier of a gel, paste, or a microparticle. 
     
     
         10 . The process of  claim 1  wherein said purine base is a purine base of 2-fluoroadenine. 
     
     
         11 . The process of  claim 1  wherein said prodrug is injected directly into proximity to the targeted cells in multiple doses. 
     
     
         12 . The process of  claim 1  wherein said prodrug is injected directly into proximity to the targeted cells in at least three consecutive doses. 
     
     
         13 . The process of  claim 1  wherein said prodrug is injected approximately evenly throughout the solid tumor through multiple doses. 
     
     
         14 . The process of  claim 1  wherein solid tumor includes a non-cycling compartment into which said prodrug is directed injected. 
     
     
         15 . The process of  claim 1  wherein said prodrug is injected directly into proximity to the targeted cells in a dose of from 3 to 24 miligrams.