Radiopharmaceutical conjugate compound for diagnosis and/or therapeutic uses thereof
The present invention provides a conjugate compound comprising a nanoparticulated enhanced permeability and retention (EPR) agent, which is an albumin, conjugated with one or more chelating agents, one or more target specific ligands and one or more detectable agents and optionally comprising one or more heterobifunctional crosslinkers and one or more pharmaceutically acceptable therapeutic agents. Further, the present invention provides a radiopharmaceutical composition and a kit comprising the said conjugate and also provides application of the same in diagnosis and therapy of various disease like cancer.
1 . A conjugate compound consisting of the formula:
H-(L) i -(X) m
wherein:
i) H is albumin;
ii) L is a chelating agent selected from the group consisting of 22,2′,2″,2″-(1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid (DOTA), 2,2′,2″-(1,4,7-triazacyclononane-1,4,7-triyl)triacetic acid (NOTA), trientine hydrochloride (TETA), 1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)]amino-6-methylperhydro-1,4-diazepine) (AAZTA), Nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), 1,4,7,10-Tetraazacyclododecane-1,4,7-triacetic acid (DO3A), NOC, DOTAGA, and/or combinations thereof; and
iii) X is a radioisotope selected from the group consisting of copper-64, copper-67, fluorine-18, gallium-68, gallium-67, gallium-66, lutetium-177, yttrium-86, yttrium-90, zirconium-89, bismuth-213, bismuth-212, actinium-225, astatine-211, gold-198, gold-199, lead-212, rhenium-188, rhenium-186, and/or combinations thereof; and
wherein i is an integer of value 1-5 and m is an integer of 1-5; and
wherein the said conjugate compound has a mean particle size distribution (d 50 ) of from about 25 nm to about 90 nm and the minimum particle size distribution (d 10 ) of the conjugate compound ranges from about 15 nm to about 40 nm and the maximum particle size distribution (d 90 ) of the conjugate compound ranges from about 40 nm to about 150 nm; and
wherein the conjugate compound has a polydispersity index less than 0.5; and
wherein the conjugate compound further consists of one or more target specific ligands conjugated to the albumin; and
wherein the conjugate compound has an initial radiochemical purity of at least 95% immediately after preparation.
2 . The conjugate compound according to claim 1 , wherein the albumin is selected from the group consisting of human serum albumin (HSA), bovine serum albumin (BSA), recombinant albumin, recombinant human albumin, ovalbumin, alpha lactalbumin and/or combinations thereof.
3 . The conjugate compound according to claim 1 , wherein the conjugate compound has an initial radiochemical purity of at least 90% for at least 3 hours post labeling at room temperature after preparation.
4 . A method of diagnosis and/or treatment of ovarian cancer, breast cancer, prostate cancer, thyroid cancer, neuroendocrine tumors (NETs), pancreatic cancer, non-small cell lung cancer (NSCLC), and/or combinations thereof comprising administering the conjugate compound according to claim 1 .
5 . A method of imaging sentinel lymph nodes comprising administering the conjugate compound according to claim 1 by PET or SPECT scans.
6 . The conjugate compound according to claim 1 , wherein L is 22,2′,2″,2″-(1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid (DOTA) and X is selected from gallium-68 and lutetium-177.