Pretargeting kit, method and agents used therein

\u3cp\u3eDescribed 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 alkene or alkyne dienohile.\u3c/p\u3

Pretargeting kit, method and agents used therein

\u3cp\u3eDescribed 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 a cyclooctene or cyclooctyne.\u3c/p\u3

Pretargeting kit, method and agents used therein

\u3cp\u3eDescribed 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 alkene or alkyne dienohile.\u3c/p\u3

Pretargeting kit, method and agents used therein

\u3cp\u3eDescribed 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 a cyclooctene or cyclooctyne.\u3c/p\u3

Evaluation of strained alkynes for Cu-free click reaction in live mice

\u3cp\u3eIntroduction: We report on our evaluation of the strain-promoted cyclooctyne-azide cycloaddition reaction for use in tumor pretargeting, comprising a side-by-side comparison of probes 1-3 bearing three distinct cyclooctyne moieties based respectively on the 1st and 2nd generation difluorinated cyclooctyne and the 1st generation dibenzocyclooctyne. Methods: The probes were synthesized and labeled with \u3csup\u3e177\u3c/sup\u3eLu with high yields. The probe stability and reactivity towards azides were evaluated in PBS and mouse serum, and their blood clearance, biodistribution and in vivo reactivity were evaluated in tumor-free mice. Results: In serum the three probes exhibited sufficient stability for a pretargeting application with half-lives of 12-19h. In PBS, probes 2 and 3 were more reactive towards azido-conjugated Rituximab (Rtx-N\u3csub\u3e3\u3c/sub\u3e) than 1, but in contrast to 1, their reactivity decreased in mouse serum and mouse serum albumin solutions, as a result of covalent and non-covalent interactions with albumin. Biodistribution data confirmed the interactions with serum proteins in circulation: \u3csup\u3e177\u3c/sup\u3eLu-1 showed a fast elimination from blood (t\u3csub\u3e1/2,β\u3c/sub\u3e = 0.31h), while \u3csup\u3e177\u3c/sup\u3eLu-2 and \u3csup\u3e177\u3c/sup\u3eLu-3 were retained in blood for longer periods of time (t\u3csub\u3e1/2,β\u3c/sub\u3e = 1.08 and 3.58h, respectively). Dual isotope biodistribution experiments assessing the reaction between \u3csup\u3e125\u3c/sup\u3eI-Rtx-N\u3csub\u3e3\u3c/sub\u3e and \u3csup\u3e177\u3c/sup\u3eLu-1-3 in circulation in mice showed a very limited retention of 2 and 3 in blood rich organs, indicating a minimal reactivity, while no such retention was observed for 1. Conclusion: The low reactivity of the studied cyclooctynes, and their serum interactions preclude their use at the low in vivo concentrations typical for pretargeting applications.\u3c/p\u3

In vivo chemistry for pretargeted tumor imaging in live mice

\u3cp\u3eFigure Presented Mice and men: An antibody conjugate with trans-cyclooctene was administered to tumor-bearing mice, and the resulting chemically tagged tumors were subsequently treated with an \u3csup\u3e111\u3c/sup\u3eIn-labeled tetrazine probe in an inverse-electrondemand Diels-Alder reaction. The adduct was formed in a remarkable 52-57% yield in vivo and used for non-invasive pretargeted tumor imaging in mice (see pietu re).\u3c/p\u3