The SAR-bisPSMA in Biochemically Recurrent Prostate Cancer (COBRA) trial is a phase I/II PET trial of up to 50 patients with biochemical recurrence of prostate cancer following definitive therapy. The primary objective of the COBRA trial is to assess the safety and tolerability of Cu-64 SAR-bisPSMA, a radiotracer designed to detect whether prostate cancer has reappeared after treatment.

Preliminary studies have shown Cu-64 SAR-bisPSMA demonstrates high uptake in tumors and is effective in PET imaging in patients with metastatic castration-resistant prostate cancer from one to 72 hours after tracer injection.