Highlights

  • Clarity has reached the recruitment target for the Main Group of the Cohort Expansion in its Phase I/IIa SECuRE trial.
  • Sixteen participants with mCRPC are being evaluated for up to six cycles of 8 GBq 67Cu-SAR-bisPSMA.
  • Recruitment continues for an arm combining 67Cu-SAR-bisPSMA with enzalutamide.
  • Clarity said it is already planning a registrational theranostic Phase III trial.

Clarity Pharmaceuticals Limited (ASX:CU6) has announced that it has achieved the recruitment target for the Main Group of the Cohort Expansion in its Phase I/IIa SECuRE trial. The trial is evaluating the company's copper-based theranostic product, SAR-bisPSMA, in patients with metastatic castration-resistant prostate cancer (mCRPC).

Cohort Expansion Recruitment Milestone

The Main Group includes 16 participants with mCRPC who are being evaluated for the efficacy and safety of up to six cycles of 8 GBq 67Cu-SAR-bisPSMA. This dose level was selected for the Cohort Expansion following a recommendation from the trial's Safety Review Committee.

Recruitment is continuing for a separate arm that combines 8 GBq 67Cu-SAR-bisPSMA with enzalutamide, an androgen receptor pathway inhibitor. Clarity said further Cohort Expansion updates are expected in the coming months as data matures.

Earlier Efficacy and Safety Data

Data reported on 5 August 2026 covered 19 participants who received a median of two cycles at 8 GBq. Among evaluable participants, 74% recorded a PSA reduction of at least 25%, 63% a reduction of at least 50%, 53% a reduction of at least 75% and 26% a reduction of at least 90%.

Among 16 radiographically evaluable participants at 8 GBq, 81% achieved disease control. This included 50% with stable disease and 31% with a complete response or undetectable disease. The company stated that most related adverse events were mild or moderate and transient.

Pathway Towards Registrational Trials

Executive Chairperson Dr Alan Taylor described the recruitment milestone as significant for Clarity's theranostic program and said, "we are already in planning for a registrational theranostic Phase III trial." He also noted that two registrational diagnostic trials are nearing readouts early next year.

SECuRE is a multi-centre, single-arm study in the US planning to enrol about 54 participants. It uses 64Cu-SAR-bisPSMA for imaging and patient selection, and 67Cu-SAR-bisPSMA for therapy. Both products are unregistered and have not been assessed by the FDA or TGA.

Key Takeaways

  • Clarity has completed recruitment for the 16-participant Main Group of the SECuRE Cohort Expansion.
  • A combination arm with enzalutamide is still recruiting.
  • Earlier data showed disease control in 81% of radiographically evaluable participants at 8 GBq.
  • The company is planning a registrational Phase III theranostic trial.