Blue Earth Diagnostics, a Bracco company and recognized leader in the development and commercialization of innovative positron emission tomography (PET) radiopharmaceuticals, today 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, multicenter, 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.
The study met its primary endpoint, demonstrating statistically significant lower urinary bladder radioactivity with POSLUMA compared with piflufolastat F 18, as measured by mean standardized 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 (interquartile range, 8.5–27.0; p<0.001). Lower urinary radioactivity may help optimize image assessment in regions close to the bladder and ureters, where small recurrent prostate cancer lesions can be challenging to distinguish from urinary activity.
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 (≤0.2 ng/mL). In this subgroup, majority-read patient-level detection rates were 52.4% with POSLUMA and 38.1% with piflufolastat F 18. Detection rates were also higher with POSLUMA in the prostate bed and extra-pelvic regions.
No significant safety concerns were observed for either radiopharmaceutical.
Biochemical recurrence refers to a rising PSA level after surgery in a patient who previously had undetectable PSA and can be an early sign that prostate cancer has returned, even before it is visible on conventional imaging. PET tracers that can help clearly show small areas of recurrent disease at very low PSA levels may support earlier and more informed clinical care decisions1.
“For men who have already undergone surgery for prostate cancer, a rising PSA can be deeply concerning, especially when conventional imaging cannot clearly show whether or where the disease has returned,” said Dr. Eugene Teoh, Chief Medical Officer of Blue Earth Diagnostics. “This head-to-head study provides important clinical evidence from a rigorous intra-patient comparison, demonstrating that POSLUMA exhibits significantly lower urinary radioactivity while maintaining meaningful detection capability in men with early biochemical recurrence. Urinary activity can impact image interpretation, which is of particular consideration at very low PSA levels, where precise localization is critical. These results reinforce the role of POSLUMA as a PSMA-PET imaging agent intelligently designed to support confident image assessment in anatomically challenging regions and reflect our continued commitment to advancing molecular imaging through high-quality clinical evidence.”
“This rigorous head-to-head study provides high-quality evidence that POSLUMA has significantly lower urinary bladder radioactivity compared to piflufolastat F 18, confirming prior studies,” said Phillip Kuo, Kuo Radiology LLC. “POSLUMA also exhibited higher detection rates for recurrence compared to piflufolastat F 18, which highlights its potential to improve patient management.”
Results from Blue Earth Diagnostics’ head-to-head study have been published in the European Journal of Nuclear Medicine and Molecular Imaging and were just presented at the 2026 ASCO Genitourinary Cancers Symposium (ASCO GU), on February 26, 2026, in San Francisco, California.
About the Head-to-Head Comparator Study
A prospective, multicenter, intra-patient head-to-head comparator study evaluating the urinary bladder 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. A total of 55 patients were evaluated with BCR and PSA levels ≤0.5 ng/mL. The study’s primary endpoint was a calculated difference in bladder SUVmean as determined by quantification software. Secondary endpoints were detection rate analyses including patient level and subgroups, PSA level, prostate bed and related subregions, and pelvic lymph nodes.