Radiotracer Derivatives Of Trimethoprim For Diagnostic Imaging

Abstract

The present invention provides radiolabeled trimethoprim which are useful in imaging tests such as PET scans. The compounds show robust bacterial uptake in vitro and identify infections from inflammation or tumor when administered to a subject. The compounds show rapid and sensitive detection of Ec DHFR containing tumors from control tumors and background tissue. In one aspect, a compound having the structure of formula (I) is provided or a pharmaceutically acceptable salt or prodrug thereof, wherein R is defined herein. Also provided are compositions containing these compounds, positron emission tomography reporter probe comprising these compounds, and methods of imaging a bacterial infection, tracking or monitoring bacteria, distinguishing a bacterial infection from inflammation or tumor, monitoring genetically fused protein expression, and monitoring genetically engineered cells in clinical scenarios such as immunotherapy for cancer treatment.

What is claimed is: 
     
         1 . A method of monitoring immunotherapy in a subject, said method comprising:
 (a) genetically engineering cells from said patient to express dihydrofolate reductase;   (b) tagging said engineered cells with a compound of formula (I):   
       
         
           
           
               
               
           
         
          wherein, R is —O—C 11 —(C 1  to C 6  alkyl), an O—C 11 -glycol, —O—(C 1  to C 6  alkyl)- 18 F, —OCH 2 -( 18 F substituted phenyl), —OCH 2 CH 2 -( 18 F-substituted triazole), —OCH 2 CH 2 -( 18 F-substituted tetrazole),  18 F-substituted boron-dipyrromethene, —O(CH 2 CH 2 O) n CH 2 CH 2 - 18 F, —OCH 2 CH 2 CH 2 NHC(O)(CH 2 CH 2 O) n —CH 2 CH 2 - 18 F, -L 1 - 68 Ga, -L 1 - 64 Cu, -L 1 - 99m Tc, radioactive halogen,  211 At, -L 1 - 10 B, -L 1 - 32 P, -L 1 - 90 Y, -L 1 - 103 Pd, -L 1 - 131 Cs, -L 1 - 153 Sm, -L 1 - 177 Lu, -L 1 - 211 At, -L 1 - 212 Bi, -L 1 - 212 Po, -L 1 - 212 Pb, -L 1 - 223 Ra, or -L 1 - 225 Ac;
 n is 1-3; 
 L 1  is a linker; 
 or a pharmaceutically acceptable salt or prodrug thereof, 
 
         (c) administering said genetically engineered and tagged cells to said patient; and 
         (d) tracking said genetically engineering cells and tagged cells by imaging.