A Phase 1, Multi-Center, Open-Label, Dose-Escalation Study of ¹³¹I-CLR1404 in Subjects with Relapsed or Refractory Advanced Solid Malignancies

This study explores the imaging and therapeutic properties of a novel radiopharmaceutical, ¹³¹I-CLR1404. Phase 1a data demonstrated safety and tumor localization by SPECT-CT. This 1b study assessed safety, imaging characteristics, and possible antineoplastic properties and provided further proof-of- concept of phospholipid ether analogues retention within tumors. A total of 10 patients received ¹³¹I-CLR1404 in an adaptive dose-escalation design. Imaging characteristics were consistent with prior studies, showing tumor uptake in primary tumors and metastases. At doses of 31.25 mCi/m² and greater, DLTs were thrombocytopenia and neutropenia. Disease- specific studies are underway to identify cancers most likely to benefit from ¹³¹I-CLR1404 monotherapy.