Trial of novel imaging agent 64Cu SAR-Bombesin in prostate cancer hits enrollment milestone

Half of the enrollment goal has been met for the phase 2 BOP trial exploring the novel imaging agent 64Cu SAR-Bombesin in patients with prostate cancer.1

64Cu SAR-Bombesin targets the Gastrin Releasing Peptide receptor (GRPr), which is found on prostate tumors as well as several other tumors.

The BOP trial is specifically exploring the safety and efficacy of 64Cu SAR-Bombesin in 2 groups of patients: men with suspected biochemical recurrence of their prostate cancer whose PSMA-PET imaging scans are negative or show low PSMA expression; and men with metastatic castration-resistant prostate cancer who are ineligible to receive PSMA therapy.

Overall, the trial has enrolled 15 patients of the targeted enrollment goal of 30 patients.

“We are very excited with the fast pace of recruitment into the BOP trial. We dosed the first patient in mid-September and have reached a 50% recruitment milestone less than 2 months later. The data we are generating will help to explore and validate the clinical benefits of the SAR-Bombesin product. We look forward to recruiting the remaining 15 patients in the trial and analyzing the study results,” Louise Emmett, MBChB, FRACP, MD, St Vincent’s Hospital Sydney, principal investigator for the BOP trial, stated in a press release.

“We believe SAR-Bombesin will play a role in the identification of disease that is not observed with conventional imaging or PSMA-PET. This could ultimately lead to more effective treatments for this large patient population where unfortunately, very few treatment options are available at present,” added Emmett.

64Cu SAR-Bombesin is also being explored in the multicenter, single-arm, non-randomized, open-label phase 2 SABRE trial (NCT05407311), which is exploring the imaging agent in patients with PSMA-negative biochemically recurrent prostate cancer.

“The BOP trial builds on the data Professor Emmett’s team generated in PSMA-negative prostate cancer patients imaged under the Therapeutic Goods Administration Special Access Scheme, as well as from the pilot diagnostic trial investigating SAR-Bombesin in breast cancer patients. The data indicates potential utility of the product as a theranostic agent. As such, Clarity plans to progress the therapy under an Investigational New Drug application with the US Food and Drug Administration for the commencement of a theranostic trial with SAR-Bombesin in the US. We believe SAR-Bombesin has the potential to provide large patient populations with accurate and precise detection and treatment of cancers,” Dr. Alan Taylor, executive chairman of Clarity, the developer of 64Cu SAR-Bombesin, stated in the press release.


1. 50% recruitment milestone reached for Phase II BOP prostate cancer trial. Published online November 2, 2022. Accessed November 4, 2022.