Clarity Pharmaceuticals has dosed the first participant in the therapeutic phase of its Phase I/II theranostic trial of 64Cu/67Cu SAR-bisPSMA theranostic products for metastatic, castrate-resistant prostate cancer (mCRPC) treatment.

The SECuRE trial has been designed for evaluating Clarity’s Targeted Copper Theranostics (TCTs) 64Cu/67Cu SAR-bisPSMA in these patients.

The trial’s first participant was treated at the Urology Cancer Center and GU Research Network located in Omaha, Nebraska.

The single arm, multi-centre, dose escalation study will identify and treat Prostate-Specific Membrane Antigen (PSMA) expressing mCRPC using TCTs.

It initially underwent the dosimetry phase with 64Cu SAR-bisPSMA for determining the product biodistribution and dosimetry over multiple time points.

A safety review committee has collected and reviewed the data and recommended to progress the trial into therapeutic applications with 67Cu SAR-bisPSMA.

The trial will determine the safety and efficacy of 67Cu -SAR-bisPSMA as a therapy.

Clarity executive chairman Dr Alan Taylor said: “Prostate cancer is one of the largest oncology indications and there is a significant unmet need for improved diagnosis and therapy of patients with this insidious disease.

“Moreover, the preliminary data suggests the optimised PSMA product could deliver clinical benefits in oncology indications beyond prostate cancer, which we are excited to explore in the near future.

“Clarity’s TCTs are the next-generation platform that aims to resolve these challenges and enable the radiopharmaceutical field to expand significantly in the large oncology market, addressing multiple large cancer indications.”

The 64Cu SAR-bisPSMA is designed to visualise the PSMA expressing lesions and choose candidates for subsequent therapy.

The company stated that the SECuRE trial has planned a cohort expansion for up to 44 participants in the US.