A single-molecule copper-64/copper-67 pair instead of switching ligands between scan and treatment
Most PSMA treatments use one molecule to take the pre-treatment scan and a slightly different molecule for the actual treatment, so the scan is only an approximate guide. A copper-based pair uses the identical molecule for both steps, just with a different form of copper, so the scan should be a much truer preview of where the treatment radiation will go.
Overview
The standard PSMA theranostic workflow images patients with 68Ga-PSMA-11 or a related diagnostic ligand and then treats responders with 177Lu-PSMA-617, a chemically different molecule; differences in the two ligands' binding and pharmacokinetics mean the diagnostic scan is only an approximate predictor of the therapeutic biodistribution. Clarity Pharmaceuticals' SAR-bisPSMA programme instead uses one identical molecule labelled with two isotopes of the same element: copper-64 for PET imaging and copper-67 for beta-emitting therapy, so in principle the diagnostic scan should be a much closer match to the therapeutic distribution than a cross-ligand, cross-element approach.
The combination is being tested in the ongoing SECuRE trial (NCT04868604), a US multi-centre, single-arm phase I/IIa study in metastatic castration-resistant prostate cancer, aiming to enrol approximately 54 participants. Company-reported interim results (data cut-off 20 July 2026) from 19 participants treated at the 8 GBq 67Cu-SAR-bisPSMA dose level showed a PSA50 response rate of 63% and PSA90 of 26%, with 81% of radiographically evaluable participants achieving disease control, including 31% with a complete response or undetectable disease by RECIST, bone scan or PSA; no dose-limiting toxicities have been reported across dose-escalation cohorts up to 12 GBq, and the sponsor states registrational phase 3 planning is under way.
These results come from company press releases and conference-style updates rather than an independent peer-reviewed publication, and the trial is a single-arm study, so there is no direct comparison yet against 177Lu-PSMA-617 or another PSMA radioligand therapy to establish whether the same-molecule imaging/therapy matching translates into a measurable clinical advantage over the established gallium-68/lutetium-177 approach.
Similar pages
not linked directly; found by shared links- CompanyNuclidium
Shares Copper-67, Copper-64, Metastatic castration-resistant prostate cancer, PSMA.
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Shares 64Cu-SAR-bisPSMA and 67Cu-SAR-bisPSMA for Identification and Treatment of PSMA-expressing Metastatic Castrate Resistant Prostate Cancer (SECuRE), Copper-67, Copper-64, Metastatic castration-resistant prostate cancer.
- CompanyClarity Pharmaceuticals
Shares 64Cu-SAR-bisPSMA and 67Cu-SAR-bisPSMA for Identification and Treatment of PSMA-expressing Metastatic Castrate Resistant Prostate Cancer (SECuRE), Copper-67, Copper-64, PSMA.
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Shares Metastatic castration-resistant prostate cancer, PSMA, Gallium-68, Lutetium-177 and the tag prostate.
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