64Cu-SAR-bisPSMA PET/CT Doubles Prostate Cancer Lesion Detection vs 68Ga-PSMA-11 in Phase 2 Trial
Phase 2 Co-PSMA trial shows 64Cu-SAR-bisPSMA PET/CT detected 63 prostate cancer lesions vs 24 with 68Ga-PSMA-11, with 78% vs 36% positive scans. Results changed management in 44% of patients.
A phase 2 head-to-head trial has shown that 64Cu-SAR-bisPSMA PET/CT more than doubled the detection of prostate cancer lesions compared with 68Ga-PSMA-11 PET/CT in patients with biochemical recurrence of prostate cancer. The imaging results changed planned patient management in 44 percent of patients.
The Co-PSMA trial (NCT06907641) enrolled 50 patients with biochemical recurrence who were candidates for curative salvage therapy. Patients were eligible if they had undergone radical prostatectomy with no salvage therapy and had a prostate-specific antigen level between 0.2 and 0.75 ng/mL. Participants received 68Ga-PSMA-11 PET/CT followed by 64Cu-SAR-bisPSMA PET/CT within 3 weeks, with 64Cu imaging at 1 hour and 24 hours post-injection on the same digital PET camera. The primary endpoint was the difference in mean per-patient lesion number.
64Cu-SAR-bisPSMA PET/CT detected an average of 1.26 prostate cancer lesions per patient compared with 0.48 with 68Ga-PSMA-11 (difference, 0.78; 95% CI, 0.52 to 1.04; ratio, 2.63; 95% CI, 1.64 to 4.20; P < .0001). Across all participants, next-day imaging with 64Cu-SAR-bisPSMA revealed 63 lesions, while 68Ga-PSMA-11 detected 24 lesions.
At the per-patient level, 78 percent (39 of 50) of patients had a positive scan with 64Cu-SAR-bisPSMA next-day imaging, compared with 36 percent (18 of 50) with 68Ga-PSMA-11. In patients with an evaluable standard of truth (n = 28), the true positive rate was 75 percent (21 of 28) with 64Cu-SAR-bisPSMA versus 39 percent (11 of 28) with 68Ga-PSMA-11.
The study was led by Prof Louise Emmett at St Vincent's Hospital Sydney. Detailed results from the Co-PSMA study will be presented at the European Association of Urology Congress 2026 in London, UK in March 2026.
The results from Co-PSMA build on previous data from the phase 1/2 COBRA trial (NCT05249127), which showed that 64Cu-SAR-bisPSMA identified more prostate cancer lesions and more patients with a positive scan compared with standard-of-care PSMA-PET agents in the biochemical recurrence setting.