Evaluation of ATO-101™ in Patients With Non-Muscle-Invasive Bladder Cancer (PERSEVERANCE EU)

Non-Muscle-Invasive Bladder cancer (NMIBC) tumours often recur despite TransUrethral Resection of Bladder (TURB) and Bacillus Calmette-Guerin (BCG) intravesical instillations, and have no effective conservative treatment options. Alpha emitters like Astatine-211 (211At), due to their short path and short half-life, show promise for superficial targets such as NMIBC. Carbonic anhydrase IX (CAIX), overexpressed in 70-90% of NMIBC cases but absent in healthy tissues, is an ideal target. A clinical feasibility Positron emission tomography-computed tomography (PET/CT) imaging study (Pertinence, NCT04897763) was conducted at Institut de cancérologie Ouest (ICO) in six patients using Girentuximab labelled with Zirconium-89 (\[89Zr\]Zr-girentuximab). It demonstrated successful tracer targeting and no radioactive leakage beyond the bladder following intravesical instillation. The study also confirmed the absence of toxicity, contamination, or significant additional staff radiation exposure. ATO-101™ (\[²¹¹At\]At-girentuximab) could enable localised tumour destruction while preserving the bladder in patients with BCG-unresponsive NMIBC. The ongoing First In Human (FIH) study evaluate the safety of ATO-101™ in patients with BCG-unresponsive NMIBC.