UK-based Blue Earth Diagnostics, a Bracco Group company focused on the development and commercialisation of innovative positron emission tomography (PET) radiopharmaceuticals, on Friday announced results from the first head-to-head study comparing urinary bladder radioactivity between two prostate-specific membrane antigen (PSMA)-targeted PET radiopharmaceuticals.

This prospective, multicentre, intra-patient comparison evaluated urinary radioactivity and lesion detection rates of POSLUMA (flotufolastat F 18) and piflufolastat F 18 in men with low prostate-specific antigen (PSA) biochemical recurrence (BCR) of prostate cancer following radical prostatectomy.

According to Blue Earth Diagnostics, the study met its primary endpoint, demonstrating statistically significant lower urinary bladder radioactivity with POSLUMA compared with piflufolastat F 18, as measured by mean standardised uptake value (SUVmean). Across 55 evaluable patients, median bladder SUVmean was 10.9 for POSLUMA and 29.0 for piflufolastat F 18, with a median difference of 15.1.

Secondary analyses showed higher patient-level and region-level detection rates with POSLUMA compared with piflufolastat F 18, including among patients with very low PSA levels (less than or equal to 0.2 ng/mL).