[177Lu]Lu-DOTA-STR-17126

This is an open-label, first-in-human, exploratory Phase 0 study evaluating the safety and diagnostic imaging performance of the DOTA-STR-17126 theranostic pair in patients with advanced or metastatic breast or prostate cancer. The study investigates \[68Ga\]Ga-DOTA-STR-17126 for PET imaging and, in patients with positive GRPR uptake, a low dose of \[177Lu\]Lu-DOTA-STR-17126 for SPECT imaging and dosimetry. The primary objective is to assess safety and tolerability. Secondary objectives include evaluation of imaging quality, biodistribution, pharmacokinetics, and radiation dosimetry. Exploratory objectives assess correlations between GRPR expression in tumour tissue and imaging uptake. The study is conducted at a single centre in Australia, with 12 evaluable participants (up to 20 enrolled), and supports the development of a GRPR-targeted theranostic approach for personalised cancer management.