EAU 2026: 64Cu-SAR-bisPSMA shows improved detection vs 68Ga-PSMA-11 in BCR of prostate cancer

Data from the phase 2 Co-PSMA trial (NCT06907641) suggest that next-day imaging with ⁶⁴Cu–SAR-bisPSMA may improve detection of recurrent disease compared with standard-of-care (SOC) 68Ga-PSMA-11 PET/CT in patients with biochemical recurrence (BCR) of prostate cancer following radical prostatectomy.

The findings, presented at the 41^st Annual European Association of Urology Congress,¹ demonstrated higher lesion detection rates, improved diagnostic accuracy, and a substantial impact on clinical management.

"Head-to-head trials are very important in helping clinicians determine the most appropriate products for their patients,” explained presenting author and principal investigator Louise Emmett, MD, MBChB, FRACP, of St Vincent's Hospital Sydney, Australia.² “The Co-PSMA study shows that a novel PSMA-targeted PET agent like ⁶⁴Cu-SAR-bisPSMA can deliver improved imaging performance compared to other SOC PSMA agents. In Co-PSMA, ⁶⁴Cu-SAR-bisPSMA at 24 hours identified more sites of recurrence and directly informed personalised treatment decisions, highlighting its potential to improve outcomes in prostate cancer patients with BCR."

The investigator-initiated Co-PSMA trial was a prospective, paired-comparison study evaluating the diagnostic performance of ⁶⁴CuS-AR-bisPSMA vs ⁶⁸Ga-PSMA-11 PET/CT in 50 patients with BCR after radical prostatectomy who had not received prior salvage radiotherapy. All patients had low prostate-specific antigen levels (between 0.2 to 0.75 ng/mL). Those included in the study underwent ⁶⁸Ga-PSMA-11 PET/CT followed by ⁶⁴Cu-SAR-bisPSMA PET/CT at 1 hour and 24 hours post-injection (same-day and next-day imaging, respectively) on the same digital PET camera.

The primary end point was the difference in mean number of lesions detected per patient. Secondary end points included diagnostic accuracy based on a composite reference standard, inter-reader agreement, and impact on clinical management.

At baseline, the median PSA level was approximately 0.43 ng/mL (IQR, 0.31 to 0.63), and 74% of patients had International Society of Urological Pathology (ISUP) grade group 3 or higher disease.

Across the cohort, ⁶⁴Cu-SAR-bisPSMA demonstrated a significantly higher mean number of lesions per patient compared with ⁶⁸Ga-PSMA-11. Specifically, the mean per-participant lesions detected was 1.26 with ⁶⁴Cu-SAR-bisPSMA vs 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). Overall, 63 lesions were identified with ⁶⁴Cu-SAR-bisPSMA compared with 24 using 68Ga-PSMA-11.

According to Clarity Pharmaceuticals, “The increase in the number of lesions identified by ⁶⁴Cu-SAR-bisPSMA was noted in the prostatic bed region (local recurrence) [56% vs 22%], pelvic/extra-pelvic lymph nodes [20% vs 8%], and bone [16% vs 10%].”

On a per-patient basis, 78% of patients had a positive scan with ⁶⁴Cu-SAR-bisPSMA vs 36% with ⁶⁸Ga-PSMA-11.

Diagnostic performance also favored ⁶⁴Cu-SAR-bisPSMA. Among evaluable patients, the true-positive rate was 71% compared with 29% for ⁶⁸Ga-PSMA-11, while false-negative rates were 21% and 65%, respectively. Inter-reader agreement was higher with the copper-based tracer (0.94 vs 0.75).

Importantly, imaging findings led to a change in planned management in 44% of patients, most commonly from surveillance to targeted radiotherapy.

According to Clarity Pharmaceuticals, these results, in combination with previous findings from the phase 2 COBRA study and anticipated results from the ongoing AMPLIFY trial, will be submitted to the FDA to support market authorization of ⁶⁴Cu-SAR-bisPSMA in patients with BCR of prostate cancer.

REFERENCES

1. Emmett L, Papa N, Ayati N, et al. Prospective comparison of 64Copper [64Cu]SAR-bis-PSMA vs. 68Ga PSMA-11 PET CT for prostate cancer detection in patients with biochemical recurrence after radical prostatectomy (Co-PSMA trial). Presented at: 41st Annual Congress of the European Association of Urology. London, UK. March 13-16, 2026. Abstract A0750

2. Co-PSMA data presented at EAU Annual Congress 2026 with manuscript accepted for publication in the European Urology journal. News release. Clarity Pharmaceuticals. March 17, 2026. Accessed March 17, 2026. https://www.claritypharmaceuticals.com/news/co-psma-eau/