A Study of [225Ac]-FPI-2059 in Adult Participants With Solid Tumours

This is a first-in-human, Phase 1, non-randomized, multi-centre, open-label clinical trial designed to investigate the safety, tolerability, dosimetry, biodistribution, and pharmacokinetics (PK) of \[225Ac\]-FPI-2059 and \[111In\]-FPI-2058, as well as the pharmacodynamics and preliminary anti-tumour activity of \[225Ac\]-FPI-2059 in participants with neurotensin receptor 1 (NTSR1)-expressing advanced, metastatic and/or recurrent solid tumours. The study will employ a 3+3 dose escalation design to identify the recommended phase 2 dose (RP2D) and regimen of \[225Ac\]-FPI-2059 administered intravenously every 56 days. After the RP2D for \[225Ac\]-FPI-2059 is determined, enrolment will continue into an expansion cohort, to confirm the safety and tolerability of the RP2D, as well as to identify any preliminary evidence of efficacy in selected NTSR1-expressing tumour types.