Clarity’s SECuRE Trial Shows 67% of Patients Achieve Over 50% PSA Reduction
Clarity Pharmaceuticals confirms continuation of its SECuRE Phase II trial for Cu-SAR-bisPSMA without protocol changes, reporting encouraging safety and efficacy data in metastatic prostate cancer patients.
- SECuRE Phase II trial continues with no protocol modifications
- Nine participants showed mostly mild adverse events
- 66.7% achieved over 50% PSA reduction, 33.3% over 80%
- One patient reached undetectable PSA and no detectable disease
- Phase III registrational trial planning underway
SECuRE Trial Progress and Safety Review
Clarity Pharmaceuticals (ASX – CU6) has announced that its SECuRE Phase II trial evaluating Cu-SAR-bisPSMA for metastatic castration-resistant prostate cancer (mCRPC) will proceed without any changes to the existing protocol. This decision follows an interim review by the Safety Review Committee (SRC), which assessed data from nine participants enrolled up to November 2025. The SRC’s endorsement reflects a favourable safety profile and promising early efficacy signals.
Patient Profile and Treatment Regimen
The interim cohort primarily consisted of heavily pre-treated patients, with over half having undergone more than five prior anti-cancer regimens. Two-thirds presented with bone metastases, a challenging clinical scenario. Participants received at least two cycles of 8 GBq Cu-SAR-bisPSMA, with some also administered enzalutamide, an androgen receptor pathway inhibitor, in combination therapy.
Safety and Adverse Events
The safety data remain encouraging, with most adverse events (AEs) graded mild to moderate (Grade 1 or 2). The most common AEs were nausea and lymphopenia, each affecting a third of participants. Notably, some Grade 3 lymphopenia cases occurred in patients with extensive prior treatments, but no renal toxicity or cardiac issues were reported. Combination therapy with enzalutamide did not introduce new or worsening AEs.
Efficacy Signals and Patient Outcomes
Among six participants with multiple prostate-specific antigen (PSA) measurements post-treatment, all demonstrated PSA declines. Two-thirds achieved reductions exceeding 50%, and a third surpassed 80% reductions. A particularly remarkable case involved a patient with bone metastases who, after three treatment cycles, reached undetectable PSA levels and showed no signs of disease on imaging, while maintaining excellent quality of life.
Looking Ahead – Phase III and Commercial Potential
Clarity’s Executive Chairperson, Dr Alan Taylor, highlighted the trial’s progress as a strong foundation for the upcoming Phase III registrational study. The company is optimistic about Cu-SAR-bisPSMA’s potential to disrupt current prostate cancer treatment paradigms, supported by three Fast Track Designations and ongoing positive interactions with the US FDA. With an estimated combined market value of US$10-15 billion by 2030 for PSMA-targeted imaging and therapies, Clarity aims to address multiple stages of prostate cancer, from diagnosis to late-stage disease.
Recruitment continues for the Cohort Expansion Phase, targeting 24 participants, including a subset receiving combination therapy with enzalutamide. The company’s proprietary SAR technology, which securely chelates copper isotopes, underpins the theranostic approach, enabling both diagnostic imaging and targeted radiotherapy.
Bottom Line?
With robust interim data and regulatory momentum, Clarity is poised to advance Cu-SAR-bisPSMA toward a pivotal Phase III trial and potential market entry.
Questions in the middle?
- Will larger patient cohorts maintain the favourable safety and efficacy profile?
- How will combination therapy with enzalutamide impact long-term outcomes?
- What regulatory hurdles remain before commercial approval in key markets?
