Up until now, only low reactivity Tzs can be radiolabeled via direct aliphatic S.sub.N2. Unfortunately, these structures display too low reactivity for in vivo bioorthogonal chemistry approaches. Highly reactive structures such as mono-unsubstituted tetrazines (H-Tzs) have been reported to be highly sensitive to base. Extensive degradation is observed which prevents isolation of meaningful amounts for imaging studies.

In the present invention there is provided a method providing the possibility to radiolabel base sensitive tetrazine structures with significantly improved RCYs. Even tetrazines that were previously not accessible by applying standard aliphatic .sup.18F-labeling strategies can be radiolabeled. This places new classes of 18 F-fluorinated compounds within reach for application in PET imaging studies such as for diagnosis of cancers.

A method of treating a malignant solid tumor in a subject is disclosed herein. The method includes the steps of administering to the subject an immunomodulatory dose of a radiohalogenated compound that is differentially taken up by and retained within malignant solid tumor tissue, and performing in situ tumor vaccination in the subject by intratumorally injecting into (or treating via a separate method) at least one of the malignant solid tumors a composition that includes one or more agents capable of stimulating specific immune cells within the tumor microenvironment. In certain exemplary embodiments, the radiohalogenated compound has the formula: ##STR00001##
wherein R.sub.1 is a radioactive halogen isotope, n is 18 and R.sub.2 is N.sup.+(CH.sub.3).sub.3.

The present invention claims UV detectable (>210 nm) potassium [.sup.18F]fluoride diaryl- and aryl-fused [2.2.2]cryptate complexes suitable for performing radio-labeling reactions to generate [.sup.18F] fluorinated species.

The present invention relates to radiolabelled 4-(furo[3,2-c]pyridin-4-yl) derivatives and their use as radioactive tracers, and in particular their use as imaging agents.

The invention relates to a new lutetium-177 therapeutic radiopharmaceutical as an inhibitor of prostate-specific membrane antigen (iPSMA), wherein 1,4,7,10-tetraazacyclododecane-N,N,N,N-tetraacetic acid (DOTA) bonded to the heterocyclic molecule hydrazinonicotinamide (HYNIC), generates a rigid chemical structure that minimises the number of conformers and intramolecular hydrogen bonds, thereby producing a favourable spatial orientation of the active site (Lys(Nal)-NHCONH-Glu) in the molecule, for biological recognition by the PSMA protein. The new 177Lu-DOTA-HYNIC-iPSMA radiopharmaceutical accumulates, with high affinity in vivo, in tumours that overexpress the PSMA protein, acting as a radiotherapeutic agent. The purpose of the invention is to provide a new specific radiopharmaceutical (molecular target radiopharmaceutical) for the treatment of tumours with PSMA overexpression. ##STR00001##

Described is a pretargeting method, and related kits, for targeted medical imaging and/or therapeutics, wherein use is made of abiotic reactive chemical groups that exhibit bio-orthogonal reactivity towards each other. The invention involves the use of [4+2] inverse electron demand (retro) Diels-Alder chemistry in providing the coupling between a Pre-targeting Probe and an Effector Probe. To this end one of these probes comprises an electron-deficient tetrazine or other suitable diene, and the other an E-cyclooctene which has a flattened structure as a result of the position of at least two exocyclic bonds.

A method of treating a malignant solid tumor in a subject is disclosed herein. The method includes the steps of administering to the subject an immunomodulatory dose of a radiohalogenated compound that is differentially taken up by and retained within malignant solid tumor tissue, and performing in situ tumor vaccination in the subject by intratumorally injecting into (or treating via a separate method) at least one of the malignant solid tumors a composition that includes one or more agents capable of stimulating specific immune cells within the tumor microenvironment. In certain exemplary embodiments, the radiohalogenated compound has the formula:

##STR00001##

wherein R.sub.1 is a radioactive halogen isotope, n is 18 and R.sub.2 is N.sup.+(CH.sub.3).sub.3.

The present invention relates to systems, compositions, and methods for the synthesis and use of imaging agents, or precursors thereof. An imaging agent precursor may be converted to an imaging agent using the methods described herein. In some cases, the imaging agent is enriched in .sup.18F. In some cases, an imaging agent may be used to image an area of interest in a subject, including, but not limited to, the heart, cardiovascular system, cardiac vessels, brain, and other organs. In some embodiments, methods and compositions for assessing perfusion and innervation mismatch in a portion of a subject are provided.

A method of treating a malignant solid tumor in a subject is disclosed herein. The method includes the steps of administering to the subject an immunomodulatory dose of a radiohalogenated compound that is differentially taken up by and retained within malignant solid tumor tissue, and performing in situ tumor vaccination in the subject by intratumorally injecting into (or treating via a separate method) at least one of the malignant solid tumors a composition that includes one or more agents capable of stimulating specific immune cells within the tumor microenvironment. In certain exemplary embodiments, the radiohalogenated compound has the formula:

##STR00001##

wherein R.sub.1 is a radioactive halogen isotope, n is 18 and R.sub.2 is N.sup.+(CH.sub.3).sub.3.

The present invention relates to systems, compositions, and methods for the synthesis and use of imaging agents, or precursors thereof. An imaging agent precursor may be converted to an imaging agent using the methods described herein. In some cases, the imaging agent is enriched in .sup.18F. In some cases, an imaging agent may be used to image an area of interest in a subject, including, but not limited to, the heart, cardiovascular system, cardiac vessels, brain, and other organs. In some embodiments, methods and compositions for assessing perfusion and innervation mismatch in a portion of a subject are provided.