AUA 2022: Results of the Phase 1 Safety and Efficacy Prostate Specific Membrane Antigen (PSMA) Targeting Fluorophore for Image Guided Surgery in Patients Undergoing Robotic Prostatectomy

( The 2022 Annual Meeting of the American Urological Association was host to a podium session of surgical therapies in localized prostate cancer. Dr. Hao Gia Nguyen presented the results of his group’s Phase 1 trial evaluating the safety and efficacy of PSMA targeting fluorophore for image-guided surgery in patients undergoing robotic prostatectomy.

 Dr. Nguyen began the presentation by highlighting that in high-risk prostate cancer patients, 15-40% of radical prostatectomy procedures result in positive margins or missed metastatic disease in lymph nodes. PSMA is a glycoprotein found on the cell surface of prostatic cells and is overexpressed on prostate cancer tissue by 100-1000 fold with low expression in native prostate and healthy tissues. ~90% of prostate tumors express PSMA.



IS-002 is a PSMA targeting fluorescent dye that is injected intravenously and is firefly compatible. It allows for fluorescent due to be detected in real-time intra-operatively. This agent has been tested in pre-clinical animal models and shown to be safe and have value in the detection of residual disease.




The authors hypothesized that IS-002 fluorescence-guided surgery on the da Vinci Surgical System may improve oncological outcomes through precision tumor excision.


This agent has proven to be safe with only Grade 1 adverse events reported so far (24 green urine, 1 green feces, and 1 green discoloration at injection site). There were no clinically significant CBC, CMP, urinalysis, or 12-lead ECG changes.

IS-002 allowed for a strong fluorescent signal from the primary tumor, residual disease, and involved lymph nodes. 


Pathologic analysis confirmed that IS-002 targets prostate cancer cells.




With regards to the exploratory efficacy endpoints, IS-002 allowed for detection of locoregional tissue invasion in 6/24 patients, residual disease in the resection bed in 5/24 patients, and tumor positive lymph nodes in 3/24.

The authors concluded: IS-002 is safe and well-tolerated, enabling enhanced intraoperative tumor detection. Based on the very encouraging results of this phase 1 study, a randomized phase 2 study is planned. Currently planning for a Phase 2 multicenter trial involving UCSF, MSKCC, JHU, and Mayo Clinic is underway with a primary objective of efficacy and a secondary objective of safety.


Presented By: Hao Gia Nguyen, Associate Professor, Urologic Oncology, UCSF, San Fransisco, CA

Written By: Rashid Sayyid, MD, MSc – Urology Chief Resident, Augusta University/Medical College of Georgia, @rksayyid on Twitter during the 2022 Annual Meeting of the American Urological Association, New Orleans, LA, May 13 – 16, 2022