64Cu-SAR-bisPSMA shows improved prostate cancer lesion detection vs 68Ga-PSMA-11

⁶⁴Cu-SAR-bisPSMA PET/CT demonstrated superior prostate cancer lesion and patient detection vs ⁶⁸Ga-PSMA-11 PET/CT in patients with biochemical recurrence (BCR) of prostate cancer, according to topline results from the phase 2 Co-PSMA trial (NCT06907641).¹

The trial was led by Louise Emmett, MD, MBChB, FRACP, at St Vincent’s Hospital Sydney in Australia

“While approved PSMA [prostate-specific maturation antigen]-PET agents are highly specific, their low sensitivity at low [prostate-specific antigen; PSA] levels means that many patients with early rising PSA show no detectable disease, making treatment planning challenging. More sensitive diagnostics that remain highly specific are needed for effective early intervention in BCR,” explained Emmett in a news release from Clarity Pharmaceuticals on the findings.¹ “Our research demonstrates that ⁶⁴Cu-SAR-bisPSMA PET/CT offers a significant advancement in the detection of recurrent prostate cancer. Compared to ⁶⁸Ga-PSMA-11, the 24-hour ⁶⁴Cu-SAR-bisPSMA images identified the site of disease recurrence in a higher proportion of patients, directly informing tailored treatment decisions for men in BCR. These findings highlight the potential for ⁶⁴Cu-SAR-bisPSMA to improve patient outcomes.”

In total, the study enrolled 50 patients with BCR who were candidates for curative salvage therapy. Patients were eligible for enrollment if they had radical prostatectomy with no salvage therapy and a PSA level between 0.2 and 0.75 ng/mL.

For the study, participants received ⁶⁸Ga-PSMA-11 PET/CT followed by ⁶⁴Cu-SAR-bisPSMA PET/CT within 3 weeks at 1 hour and 24 hours post injection (same-day and next-day imaging, respectively), using the same digital PET camera. The primary end point was the difference in mean per-patient lesion number.

Overall, ⁶⁴Cu-SAR-bisPSMA PET/CT identified a statistically significant greater number of prostate cancer lesions per patient compared with ⁶⁸Ga-PSMA-11 PET/CT. Specifically, 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, 0.52-1.04; ratio, 2.63; 95% CI, 1.64-4.20; P < .0001).

Across all participants, ⁶⁴Cu-SAR-bisPSMA PET/CT next-day imaging detected 63 lesions, and ⁶⁸Ga-PSMA-11 detected 24 lesions.

At the per-patient level, 78% (39 of 50) patients had a positive scan indicating prostate cancer with ⁶⁴Cu-SAR-bisPSMA next-day imaging, compared with 36% (18 of 50) of patients with ⁶⁸Ga-PSMA-11. In patients with an evaluable standard of truth (n = 28), the true positive rate was 75% (21 of 28) with ⁶⁴Cu-SAR-bisPSMA vs 39% (11 of 28) with ⁶⁸Ga-PSMA-11.

⁶⁴Cu-SAR-bisPSMA imaging results changed planned patient management in 44% (22 of 50) of patients.

Detailed results from the Co-PSMA study were presented at the European Association of Urology Congress 2026 in London, UK in March 2026. According to the news release from Clarity Pharmaceuticals, 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 (SOC) PSMA-PET agents in the BCR setting.²

“Similar to COBRA, Co-PSMA demonstrated that our product was able to identify more than 2.5 times the total number of lesions on the next-day imaging in comparison to the SOC,” explained Alan Taylor, PhD, executive chairperson for Clarity Pharmaceuticals, in the news release.¹ “Furthermore, 4 out of every 5 participants had a positive scan for prostate cancer using ⁶⁴Cu-SAR-bisPSMA, compared to only 2 in 5 participants using ⁶⁸Ga-PSMA-11, therefore making ⁶⁴Cu-SAR-bisPSMA far more reliable than ⁶⁸Ga-PSMA-11 in detecting the presence of cancer in these patients. These findings, coupled with the much higher true positive rate of ⁶⁴Cu-SAR-bisPSMA (75% vs. 39% for ⁶⁸Ga-PSMA-11), will enable clinicians to treat prostate cancer more effectively and with a greater level of confidence based on the accurate detection of disease.”

REFERENCES

1. Co-PSMA: Cu-64 SAR-bisPSMA more than doubled prostate cancer lesion and patient detection vs. Ga-68 PSMA-11 in head-to-head trial. News release. Clarity Pharmaceuticals. February 16, 2026. Accessed February 16, 2026. https://www.prnewswire.com/news-releases/co-psma-cu-64-sar-bispsma-more-than-doubled-prostate-cancer-lesion-and-patient-detection-vs-ga-68-psma-11-in-head-to-head-trial-302688516.html

2. Nordquist L, Lengyelova E, Saltzstein D, et al. COBRA: assessment of ⁶⁴Cu-SAR-bisPSMA and standard of care prostate-specific membrane antigen positron emission tomography in patients with biochemical recurrence of prostate cancer following definitive therapy. J Urol. 2025;213(55):e474. doi:10.1097/01.JU.0001109868.09667.98.01