Protocol for minimizing toxicity of combination dosages and imaging agent for verification

Abstract

Advantage is taken of the enhanced permeability and retention effect (EPR effect) to shield normal tissue from exposure to combinations of chemotherapeutic agents. Imaging agents that exhibit the enhanced permeability and retention (EPR) effect in solid tumors are useful in mimicking the behavior of chemotherapeutic or other drugs for treatment of said tumor conjugated to carriers of similar size and shape to the carriers of said imaging agents.

1 . A method to ameliorate the toxicity to normal tissue in a subject resulting from administering to said subject a first and second chemotherapeutic agent in a protocol for combination therapy against a solid tumor employing said first and second agent, which method comprises:
 administering the first agent as an agent-releasing conjugate to a flexible carrier wherein the carrier is a nanoparticle or macromolecule each with a hydrodynamic radius of 5-50 nm which conjugate exhibits enhanced permeability and retention (EPR) in solid tumors so as to concentrate said conjugate in the tumor and wherein the rate of release from the tumor of the conjugate and first agent released from the conjugate is substantially slower than the rate of clearance of the conjugate and released agent from the systemic circulation of the subject;   allowing a time period for clearance of the conjugate and released agent from the systemic circulation of the subject; and   after said time period, administering said second agent to the subject.   
     
     
         2 . The method of  claim 1 , wherein the second agent is administered in free form, or
 wherein the second agent is administered as an agent-releasing conjugate to a carrier, wherein the carrier is a nanoparticle or macromolecule each with a hydrodynamic radius of 5-50 nm.   
     
     
         3 . The method of  claim 1 , which further includes administering a third agent with non-overlapping toxicity with the second agent. 
     
     
         4 . The method of  claim 1 , which further includes allowing a time period for clearance of the second agent; and
 after said time period, again administering said conjugated first agent to the subject.   
     
     
         5 . The method of  claim 1 , wherein the characteristics associated with the concentration of the conjugate in the solid tumor are measured by administering a label non-releasably coupled to the same carrier as the first agent and tracking the label in vivo in said subject. 
     
     
         6 . The method of  claim 5 , wherein the label is an isotope detectable by positron emission tomography (PET) scanning. 
     
     
         7 . The method of  claim 1 , wherein the conjugate releases said first agent by beta elimination or by hydrolysis of esters, carbonates, or carbamates, or by proteolysis of amides or by reduction of aromatic nitro groups by nitroreductase. 
     
     
         8 . The method of  claim 1 , wherein the carrier comprises a polyethylene glycol of molecular weight 10 kD-60 kD. 
     
     
         9 . The method of any of  claims 1-8 , wherein the first agent is a topoisomerase inhibitor, an anthracycline, a taxane, an epothilone, a tyrosine kinase inhibitor, an inhibitor of homologous recombination repair, a biologic, an anti-steroid, or a nucleoside. 
     
     
         10 . The method of  claim 9 , wherein the first agent is a topoisomerase inhibitor. 
     
     
         11 . The method of any of  claims 1-8 , wherein the second agent is an inhibitor of homologous recombination repair, an agent synergistic to or additive to a PARP inhibitor, or an mTOR inhibitor, trabectedin, cis-platinum, oxaliplatin, fluorouracil, temozolomide or vincristine. 
     
     
         12 . A method to minimize the toxic effects on normal tissue of a subject of a first and second chemotherapeutic agent used in combination to treat a solid tumor in said subject which method comprises administering said second agent simultaneously with said first agent, said first agent being in the form of a conjugate to a flexible carrier, wherein said conjugate exhibits enhanced permeability and retention (EPR) and effects concentration of said conjugate in said tumor,
 wherein the carrier is a nanoparticle or macromolecule with a hydrodynamic radius of 5-50 nm.   
     
     
         13 . The method of  claim 12 , wherein the second agent is conjugated or unconjugated. 
     
     
         14 . The method of  claim 12 , wherein the second agent is conjugated to a carrier with the same structure as the carrier for the first agent. 
     
     
         15 . The method of  claim 12 , wherein the characteristics associated with the concentration of the conjugate(s) in the solid tumor are measured by administering a label non-releasably coupled to the same carrier as that for at least the first agent and tracking the label in vivo in said subject. 
     
     
         16 . The method of  claim 15 , wherein the label is an isotope detectable by positron emission tomography (PET) scanning. 
     
     
         17 . The method of  claim 14 , wherein the conjugate(s) release said agents by beta elimination or by hydrolysis of esters, carbonates, or carbamates, or by proteolysis of amides or by reduction of aromatic nitro groups by nitroreductase. 
     
     
         18 . The method of  claim 12 , wherein the macromolecular carrier(s) comprise(s) polyethylene glycol of molecular weight of 10 kD-60 kD. 
     
     
         19 . The method of any of  claims 12-18 , wherein the first agent is a topoisomerase inhibitor, an anthracycline, a taxane, an epothilone, a tyrosine kinase inhibitor, an inhibitor of homologous recombination repair, a biologic, an anti-steroid, or a nucleoside. 
     
     
         20 . The method of  claim 19 , wherein the first agent is a topoisomerase inhibitor. 
     
     
         21 . The method of any of  claims 12-18 , wherein the second agent is an inhibitor of homologous recombination repair, an agent synergistic to or additive to a PARP inhibitor, or an mTOR inhibitor, trabectedin, cis-platinum, oxaliplatin, fluorouracil, temozolomide or vincristine. 
     
     
         22 . An imaging agent of the formula (1)
                       wherein PEG represents a polyethylene glycol comprising a plurality of 2-6 arms of 40-60 kD;   chelator represents a desferrioxamine or a plur-hydroxypyridinone multidentate;   I is a radioisotope suitable for positron emission tomography(PET);                         is a covalent connector;   ~ indicates sequestration of I in the chelator; and   n is an integer of 1 up to the number of arms of said PEG.   
     
     
         23 . The imaging agent of  claim 22  wherein I is  89 Zr,  94 Tc,  101 In,  81 Rb,  66 Ga,  64 Cu,  62 Zn,  61 Cu or  52 Fe; and/or
 wherein PEG is a four armed polyethylene glycol of approximately 40 kD, and n is 1-4; and/or 
 wherein the chelator is desferrioxamine-B; and/or 
 wherein 
                     
 is a direct bond linkage. 
 
 
     
     
         24 . A method to monitor accumulation of the imaging agent of  claim 22  or  23  in a tumor which method comprises administering said imaging agent and detecting the location of said imaging agent by PET. 
     
     
         25 . A method to assess the pharmacokinetics of the conjugate of a drug and its accumulation in tumor which method comprises matching the size and shape of the conjugate of said drug to the size and shape of the imaging agent of  claim 22  or  23 , administering said imaging agent to a subject bearing a tumor and monitoring the accumulation of said agent in the tumor by PET. 
     
     
         26 . A kit that includes the imaging agent of  claim 22  or  23  and a drug conjugate. 
     
     
         27 . A method to identify a subject having an undesirable tissue mass likely to benefit from treatment with a drug modified to exhibit the EPR effect, which comprises administering the imaging agent of  claim 22  or  23  to a candidate subject; and
 monitoring the distribution of the imaging agent in the subject, 
 whereby a subject that accumulates said imaging agent in said undesirable tissue mass is identified as a subject that will benefit from such treatment. 
 
     
     
         28 . The method of  claim 27  which further includes determining the presence or absence of a mutation in a gene that encodes a protein that participates in effecting DNA repair, wherein the presence of said mutation in the subject identifies the subject as having said tumor. 
     
     
         29 . The method of  claim 28  wherein the gene is BRCA1, BRCA2, ATM or ATR. 
     
     
         30 . A hybrid conjugate for treatment and imaging of solid tumors which conjugate comprises a flexible carrier wherein the carrier is a nanoparticle or macromolecule each with a hydrodynamic radius of 5-50 nm which conjugate exhibits enhanced permeability and retention (EPR) in solid tumors so as to concentrate said conjugate in the tumor and wherein said carrier is releaseably coupled to a therapeutic agent and also coupled to an imaging agent. 
     
     
         31 . The hybrid conjugate of  claim 30  which is of formula (2)
                     
 wherein PEG represents a polyethylene glycol comprising a plurality of 2-6 arms of 40-60 kD; 
 chelator represents a desferrioxamine or a plur-hydroxypyridinone multidentate; 
 I is a radioisotope suitable for positron emission tomography(PET); 
                     
 is a covalent connector; 
 ~ indicates sequestration of I in the chelator; 
 L is a linker; 
 D is a therapeutic agent; 
 n is an integer of 1 up to the number of arms of said PEG minus x; and 
 x is an integer of up to the number of arms of said PEG minus n. 
 
     
     
         32 . The imaging agent of  claim 31  wherein I is  89 Zr,  94 Tc,  101 In,  81 Rb,  66 Ga,  64 Cu,  62 Zn,  61 Cu or  52 Fe; and/or
 wherein PEG is a four armed polyethylene glycol of approximately 40 kD, and n is 1-4; and/or 
 wherein the chelator is desferrioxamine-B; and/or 
 wherein 
                     
 a is a direct bond linkage; and/or 
 
 D is SN38, BMN673, VX-970 or rucaparib. 
 
     
     
         33 . A method to correlate imaging and treatment of a solid tumor which method comprises administering to a solid tumor-bearing subject the hybrid conjugate of any of  claims 30-32  and monitoring the accumulation of said conjugate in the tumor and monitoring the volume of said tumor.