Co-PSMA prostate imaging data presented at EAU congress

SYDNEY, March 17, 2026 /PRNewswire/ -- Clarity Pharmaceuticals (ASX: CU6) ("Clarity" or "Company"), a clinical-stage radiopharmaceutical company with a mission to develop next-generation products that improve treatment outcomes for patients with cancer, is pleased to announce that the results from the Co-PSMA (NCT06907641)^[1] IIT were presented by Prof Louise Emmett (St Vincent's Hospital Sydney) in an oral session at EAU Congress 2026, Europe's largest urological conference, on the 16^th March in London, UK^[2]. The study data has also been accepted for publication in European Urology, the official journal of EAU with an impressive impact factor of 25.2.

Co-PSMA (Comparative performance of ⁶⁴Copper [⁶⁴Cu]-SAR-bisPSMA vs. ⁶⁸Ga-PSMA-11 PET CT for the detection of prostate cancer recurrence in the setting of biochemical failure following radical prostatectomy) was a Phase II IIT evaluating the performance of Clarity's diagnostic product, ⁶⁴Cu-SAR-bisPSMA, in a head-to-head comparison to SOC ⁶⁸Ga-PSMA-11 in 50 patients with low PSA (0.2 – 0.75 ng/mL) who were candidates for curative salvage therapy. Eligible patients were required to have had radical prostatectomy with no salvage therapy. ⁶⁸Ga-PSMA-11 PET/CT was 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.^[1],[3]

The primary endpoint of the Co-PSMA study was to assess the difference in mean per patient lesion number. Using a paired means test, a sample size of 50 provided power of 90% to detect a minimum alternative mean difference greater than zero of 0.432. Secondary endpoints included management impact questionnaires between ⁶⁴Cu-SAR-bisPSMA and ⁶⁸Ga-PSMA-11 and accuracy of the PET findings determined using a comprehensive reference standard, including biopsy, response to targeted treatment without androgen deprivation therapy (ADT), PSA rise without treatment or corroborative imaging.

Overall, ⁶⁴Cu-SAR-bisPSMA PET/CT (24-hour imaging) was found to identify a higher number of disease recurrences than ⁶⁸Ga-PSMA-11 PET/CT with substantial management impact and a high true positive rate in men with BCR post-radical prostatectomy.

Participants enrolled had a median PSA of 0.43 (IQR: 0.31 – 0.63) and 74% had an International Society of Urological Pathologists (ISUP) grade of 3 or higher. The mean per-patient lesion for ⁶⁴Cu-SAR-bisPSMA (24-hour imaging) was 1.26, compared to 0.48 for ⁶⁸Ga-PSMA-11, with a difference of 0.78 (95%CI: 0.52 – 1.04), ratio 2.63 (95%CI: 1.64 – 4.20) (p <0.0001). In total, ⁶⁸Ga-PSMA-11 identified 24 lesions across all participants, while 24-hour ⁶⁴Cu-SAR-bisPSMA imaging detected 63 lesions (representative image in Figure 1). The increase in the number of lesions identified by ⁶⁴Cu-SAR-bisPSMA was noted in the prostatic bed region (local recurrence), pelvic/extra-pelvic lymph nodes and bone (Table 1).

Table 1. Comparison between 68Ga-PSMA-11 and 64Cu-SAR-bisPSMA scans: number of participants with a positive scan and location of recurrence. 24-hour 64Cu-SAR-bisPSMA scans resulted in a higher number of lesions detected and prostate-specific membrane antigen (PSMA) PET-positive participants as compared to 68Ga-PSMA-11 scans. The increase in the number of lesions identified by 64Cu-SAR-bisPSMA was noted in the prostatic bed region (local recurrence), pelvic/extra-pelvic lymph nodes and bone.

On a per patient level, 36% (18/50) of participants were positive on 68Ga-PSMA-11 PET/CT, compared to 78% (39/50) on 64Cu-SAR-bisPSMA PET/CT (next-day imaging). Planned patient management changed following the assessment of the 64Cu-SAR-bisPSMA scans in 22/50 (44%) trial participants. Among the participants with an evaluable standard of truth (SOT), the true positive rate was 71% for 24-hour 64Cu-SAR-bisPSMA (24/34) compared to 29% (10/34) for 68Ga-PSMA-11. The false negative rate was 21% for 24-hour 64Cu-SAR-bisPSMA (7/34) vs. 65% for 68Ga-PSMA-11 (22/34).

These results from the Co-PSMA IIT further build on the growing body of evidence demonstrating that 64Cu-SAR-bisPSMA improves the detection of prostate cancer compared to the current SOC PSMA PET agents which have lower sensitivity in patients with low PSA levels[4],[5]. In the Phase II COBRA trial, 64Cu-SAR-bisPSMA was evaluated in patients with BCR who had a negative or equivocal scan at study entry. Among participants with a follow-up SOC PSMA PET, 90% were positive on 24-hour 64Cu-SAR-bisPSMA PET compared with only 60% on SOC PSMA PET. Overall, next-day imaging with 64Cu-SAR-bisPSMA identified more than 2.6 times lesions than SOC PSMA PET[6]. The COBRA data, combined with the Co-PSMA IIT results, will complement the anticipated findings from the Phase III registrational trial, AMPLIFY, which recently reached its target number of participants[7]. Together, they are intended to be submitted to the US FDA for a market authorisation of 64Cu-SAR-bisPSMA in patients with BCR of prostate cancer.

Prof Louise Emmett (St Vincent's Hospital Sydney), Principal Investigator in the Co-PSMA trial, commented, "Head-to-head trials are very important in helping clinicians determine the most appropriate products for their patients. 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."

Clarity's Executive Chairperson, Dr Alan Taylor, commented, "Science underpins the entirety of our biotechnology sector, and as a science-driven organisation, nothing makes us more proud than to see our products progress from the Australian benchtop to now generating excellent results in the clinic and having this substantiated and quantified to the highest standard through the scientific method. We applaud the independent work of Prof Louise Emmett and her team at St Vincent's Hospital in Sydney who chose to progress this trial in such detail, leading to the acceptance of the data in European Urology, a top-tier journal with a high impact factor of 25.2.

"The high quality of these data now adds to the substantial body of evidence supporting our product, the optimised SAR-bisPSMA. The discovery and pre-clinical work has been previously circulated in numerous journals, including publications by our long-term collaborator, Prof Paul Donnelly, sharing his seminal work on the sarcophagine (SAR) chelator as well as on the SARTATE, SAR-Bombesin and the optimised SAR-bisPSMA agents in 2023 in Chemical Reviews[8], one of the highest impact factor journals in chemistry with a 5-year impact factor of 67.5.

"The extraordinary quality of the academic research is coupled with the feverish pace of commercialisation where our registrational Phase III trials, AMPLIFY and CLARIFY, are nearing completion. We have recently shared that AMPLIFY reached its target number of participants with rising or detectable PSA after initial definitive treatment at clinical sites across the US and Australia in just 9 months since imaging the first patient[7], and we look forward to collecting and analysing the final study data. Combined with results from the Co-PSMA and COBRA trials, we believe it will constitute a compelling application for approval of 64Cu-SAR-bisPSMA by regulatory authorities for the BCR indication. Armed with three Fast Track Designations for the one SAR-bisPSMA agent, we are ready to work closely with the US FDA to get it to patients in need as soon as possible, and we look forward to more positive interactions with the Agency on this journey. As always, we will continue updating the market on the progress of our bisPSMA program, including significant milestones in the AMPLIFY, CLARIFY and SECuRE trials, as well as on the supply chain and regulatory developments as we enter the market with our first product."

www.claritypharmaceuticals.com

This announcement has been authorised for release by the Executive Chairperson.