{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Orcutt KD"],"funding":["National Institute of Health"],"pagination":["5831"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC9504749"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["27(18)"],"pubmed_abstract":["[<sup>212</sup>Pb]VMT01 is a melanocortin 1 receptor (MC1R) targeted theranostic ligand in clinical development for alpha particle therapy for melanoma. <sup>212</sup>Pb has an elementally matched gamma-emitting isotope <sup>203</sup>Pb; thus, [<sup>203</sup>Pb]VMT01 can be used as an imaging surrogate for [<sup>212</sup>Pb]VMT01. [<sup>212</sup>Pb]VMT01 human serum stability studies have demonstrated retention of the <sup>212</sup>Bi daughter within the chelator following beta emission of parent <sup>212</sup>Pb. However, the subsequent alpha emission from the decay of <sup>212</sup>Bi into <sup>208</sup>Tl results in the generation of free <sup>208</sup>Tl. Due to the 10.64-hour half-life of <sup>212</sup>Pb, accumulation of free <sup>208</sup>Tl in the injectate will occur. The goal of this work is to estimate the human dosimetry for [<sup>212</sup>Pb]VMT01 and the impact of free <sup>208</sup>Tl in the injectate on human tissue absorbed doses. Human [<sup>212</sup>Pb]VMT01 tissue absorbed doses were estimated from murine [<sup>203</sup>Pb]VMT01 biodistribution data, and human biodistribution values for <sup>201</sup>Tl chloride (a cardiac imaging agent) from published data were used to estimate the dosimetry of free <sup>208</sup>Tl. Results indicate that the dose-limiting tissues for [<sup>212</sup>Pb]VMT01 are the red marrow and the kidneys, with estimated absorbed doses of 1.06 and 8.27 mGy<sub>RBE = 5</sub>/MBq. The estimated percent increase in absorbed doses from free <sup>208</sup>Tl in the injectate is 0.03% and 0.09% to the red marrow and the kidneys, respectively. Absorbed doses from free <sup>208</sup>Tl result in a percent increase of no more than 1.2% over [<sup>212</sup>Pb]VMT01 in any organ or tissue. This latter finding indicates that free <sup>208</sup>Tl in the [<sup>212</sup>Pb]VMT01 injectate will not substantially impact estimated tissue absorbed doses in humans."],"journal":["Molecules (Basel, Switzerland)"],"pubmed_title":["Dosimetry of [<sup>212</sup>Pb]VMT01, a MC1R-Targeted Alpha Therapeutic Compound, and Effect of Free <sup>208</sup>Tl on Tissue Absorbed Doses."],"pmcid":["PMC9504749"],"funding_grant_id":["NIH R01CA243014","R44CA254613","R44CA250872"],"pubmed_authors":["Cupido JM","Heimann J","Johnson FL","Orcutt KD","Lyon MC","Li M","Schultz MK","Cissell DD","Liu D","Gottumukkala V","Habjan C","Hussein AI","Henry KE","Palmer K"],"additional_accession":[]},"is_claimable":false,"name":"Dosimetry of [<sup>212</sup>Pb]VMT01, a MC1R-Targeted Alpha Therapeutic Compound, and Effect of Free <sup>208</sup>Tl on Tissue Absorbed Doses.","description":"[<sup>212</sup>Pb]VMT01 is a melanocortin 1 receptor (MC1R) targeted theranostic ligand in clinical development for alpha particle therapy for melanoma. <sup>212</sup>Pb has an elementally matched gamma-emitting isotope <sup>203</sup>Pb; thus, [<sup>203</sup>Pb]VMT01 can be used as an imaging surrogate for [<sup>212</sup>Pb]VMT01. [<sup>212</sup>Pb]VMT01 human serum stability studies have demonstrated retention of the <sup>212</sup>Bi daughter within the chelator following beta emission of parent <sup>212</sup>Pb. However, the subsequent alpha emission from the decay of <sup>212</sup>Bi into <sup>208</sup>Tl results in the generation of free <sup>208</sup>Tl. Due to the 10.64-hour half-life of <sup>212</sup>Pb, accumulation of free <sup>208</sup>Tl in the injectate will occur. The goal of this work is to estimate the human dosimetry for [<sup>212</sup>Pb]VMT01 and the impact of free <sup>208</sup>Tl in the injectate on human tissue absorbed doses. Human [<sup>212</sup>Pb]VMT01 tissue absorbed doses were estimated from murine [<sup>203</sup>Pb]VMT01 biodistribution data, and human biodistribution values for <sup>201</sup>Tl chloride (a cardiac imaging agent) from published data were used to estimate the dosimetry of free <sup>208</sup>Tl. Results indicate that the dose-limiting tissues for [<sup>212</sup>Pb]VMT01 are the red marrow and the kidneys, with estimated absorbed doses of 1.06 and 8.27 mGy<sub>RBE = 5</sub>/MBq. The estimated percent increase in absorbed doses from free <sup>208</sup>Tl in the injectate is 0.03% and 0.09% to the red marrow and the kidneys, respectively. Absorbed doses from free <sup>208</sup>Tl result in a percent increase of no more than 1.2% over [<sup>212</sup>Pb]VMT01 in any organ or tissue. This latter finding indicates that free <sup>208</sup>Tl in the [<sup>212</sup>Pb]VMT01 injectate will not substantially impact estimated tissue absorbed doses in humans.","dates":{"release":"2022-01-01T00:00:00Z","publication":"2022 Sep","modification":"2024-11-20T17:01:03.386Z","creation":"2024-11-20T17:01:03.386Z"},"accession":"S-EPMC9504749","cross_references":{"pubmed":["36144563"],"doi":["10.3390/molecules27185831"]}}