Fibroblast activation protein (fap)-targeted imaging and therapy

Abstract

The present teachings relate generally to conjugates and methods for imaging a tumor microenvironment in a patient, and to conjugates and methods for imaging cancer-associated fibroblasts (CAFs) in the tumor microenvironment of a patient. The present teachings relate generally to method of making conjugates comprising a fibroblast activation protein (FAP) inhibitor.

1 . A conjugate, or a pharmaceutically acceptable salt thereof, having a structure
   B-L-X,   wherein B comprises a fibroblast activation protein (FAP) inhibitor;   L comprises a bivalent linker; and   X comprises a near infrared (NIR) dye, a radioactive imaging agent, or a therapeutic agent effective against cancer cells and/or cancer-associated fibroblasts (CAF).   
     
     
         2 . The conjugate of  claim 1 , wherein B has a structure 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are the same or different, and are each independently selected from the group consisting of hydrogen, halogen, and C 1 -C 4  alkyl; 
         R 3  is a C 1 -C 4  alkyl, nitrile, or isonitrile; 
         R 4 , R 5 , and R 6  are the same or different, and are each independently selected from the group consisting of hydrogen, halogen, and C 1 -C 4  alkyl; and 
         n is an integer from 1 to 8. 
       
     
     
         3 .- 6 . (canceled) 
     
     
         7 . The conjugate of  claim 2 , or a pharmaceutically acceptable salt thereof, wherein B has a structure 
       
         
           
           
               
               
           
         
       
     
     
         8 . (canceled) 
     
     
         9 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, wherein the linker comprises at least one amino acid in the D- or L-configuration, or a derivative thereof, selected from the group consisting of Lys, Asn, Thr, Ser, Ile, Met, Pro, His, Gln, Arg, Gly, Asp, Glu, Ala, Val, Phe, Leu, Tyr, Cys, and Trp. 
     
     
         10 .- 15 . (canceled) 
     
     
         16 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, wherein the linker comprises a moiety of the formula 
       
         
           
           
               
               
           
         
       
       wherein m is an integer from 0 to 9, p is an integer from 3 to 10, q is an integer from 3 to 100. 
     
     
         17 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, wherein the linker comprises a portion selected from the group consisting of 
       
         
           
           
               
               
           
         
         wherein 
         each of R 7  and R 8  is independently H or C 1 -C 6  alkyl; 
         t is an integer from 1 to 8. 
       
     
     
         18 .- 20 . (canceled) 
     
     
         21 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, wherein L comprises a structure 
       
         
           
           
               
               
           
         
       
     
     
         22 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, wherein the linker comprises a portion selected from the group consisting of 
       
         
           
           
               
               
           
         
         wherein R 6  is H or C 1 -C 6  alkyl. 
       
     
     
         23 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, comprising the formula 
       
         
           
           
               
               
           
         
       
     
     
         24 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, wherein X comprises a fluorescent dye, or a NIR dye. 
     
     
         25 . (canceled) 
     
     
         26 . The conjugate of  claim 24 , or a pharmaceutically acceptable salt thereof, wherein the fluorescent dye is fluorescein maleimide or fluorescein isothiocyanate (FITC). 
     
     
         27 . The conjugate of  claim 24 , or a pharmaceutically acceptable salt thereof, wherein the NIR dye is S0456. 
     
     
         28 . (canceled) 
     
     
         29 . (canceled) 
     
     
         30 . The conjugate of  claim 1  having a structure 
       
         
           
           
               
               
           
         
       
       or a pharmaceutically acceptable salt thereof. 
     
     
         31 . (canceled) 
     
     
         32 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, wherein X is a chelating agent of the formula 
       
         
           
           
               
               
           
         
       
     
     
         33 . The conjugate of  claim 32 , or a pharmaceutically acceptable salt thereof, wherein X comprises a radioactive metal isotope coordinated to the chelating agent. 
     
     
         34 . A conjugate having a structure 
       
         
           
           
               
               
           
         
         wherein L comprises a bivalent linker; and 
         X comprises a near infrared (NIR) dye. 
       
     
     
         35 . (canceled) 
     
     
         36 . A method of surgically removing cancer-associated fibroblasts (CAFs) from a patient, the method comprising:
 delivering a conjugate to a tumor microenvironment of the patient, the tumor microenvironment comprising at least one CAF, the conjugate having a structure   
       
         
           
           
               
               
           
         
          wherein L comprises a bivalent linker and X comprises a near infrared (NIR) dye; 
         causing the NIR dye to fluoresce through an application of an optical stimulus thereto; and 
         cutting CAF-containing tissue of the patient based on a result of the fluorescence. 
       
     
     
         37 . (canceled) 
     
     
         38 . The conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, wherein A is a drug selected from the group consisting of a vinca alkaloid, a cryptophycin, bortezomib, thiobortezomib, a tubulysin, aminopterin, rapamycin, paclitaxel, docetaxel, doxorubicin, daunorubicin, everolimus, a-amanatin, verucarin, didemnin B, geldanomycin, purvalanol A, ispinesib, budesonide, dasatinib, an epothilone, a maytansine, and a tyrosine kinase inhibitor. 
     
     
         39 .- 47 . (canceled) 
     
     
         48 . A conjugate of the formula 
       
         
           
           
               
               
           
         
       
       or a pharmaceutically acceptable salt thereof. 
     
     
         49 . The conjugate of  claim 48 , or a pharmaceutically acceptable salt thereof, wherein the conjugate comprises a radioactive metal isotope selected from the group consisting of  111 In,  99m Tc,  64 Cu,  67 Cu,  67 Ga and  68 Ga coordinated thereto. 
     
     
         50 . (canceled) 
     
     
         51 . A conjugate of the formula 
       
         
           
           
               
               
           
         
       
       or pharmaceutically acceptable salt thereof. 
     
     
         52 . (canceled) 
     
     
         53 . A pharmaceutical composition comprising a conjugate of  claim 1 , or a pharmaceutically acceptable salt thereof, and optionally at least one pharmaceutically acceptable excipient. 
     
     
         54 . A method of treating cancer in a subject, comprising,
 a. administering to the subject an effective amount of a conjugate or composition according to  claim 1 ; or a pharmaceutically acceptable salt thereof.   
     
     
         55 .- 62 . (canceled) 
     
     
         63 . A method of imaging a population of cells in vitro, comprising
 a. contacting the cells with a conjugate according to  claim 1 , to provide labelled cells, and   b. visualizing the labelled cells.   
     
     
         64 . (canceled) 
     
     
         65 . (canceled) 
     
     
         66 . A method of imaging a population of cells in vivo, comprising
 a. administering to a patient an effective amount of a conjugate according to  claim 1 , or a pharmaceutically acceptable salt thereof, to provide labelled cells; and   b. visualizing the labelled cells by imaging.   
     
     
         67 . (canceled) 
     
     
         68 . (canceled)