¹³¹I-RPS-001 (¹³¹I-MIP-1095) is a small radiolabeled molecule, a glutamate-urea-lysine analogue, for therapeutic application in prostate cancer. ¹³¹I-RPS-001 is targeting the prostate-specific membrane antigen (PSMA) receptor. PSMA is a membrane-bound glycoprotein expressed mainly in the prostate epithelium. Some other solid cancers also overexpress this antigen.

After a seven-year break, a clinical study was initiated in January 2017 with this molecule. The study was completed in April 2019. This drug was considered on hold for a time, but has been reactivated and entered Phase II clinical trial in June 2019. This new study explores the potential of ¹³¹I-RPS-001 in combination with Enzalutamide in patients with mCRPC. PSMA-avidity will be determined by assessment of ¹⁸F-DCFPyL PET/CT Imaging. Completion is expected by end of 2022. Another Phase II study was initiated in September 2019 and is expected to be completed by December 2024.

Target/Mechanism: PSMA

Carrier/Ligand: RPS-001

Radiation Type: beta electrons (β^–)