Impact of Baseline Renal Insufficiency on Piflufolastat F-18 Performance and Investigation of Changes in Renal Function Following Piflufolastat F-18 Administration: Results From the OSPREY Trial

Introduction: Piflufolastat F-18, a prostate-specific membrane antigen (PSMA)-targeted radiopharmaceutical, is predominantly eliminated via urinary excretion, and the kidneys have one of the highest absorbed doses. Therefore, this subgroup analysis aimed to investigate the impact of piflufolastat F-18 on renal function and its diagnostic performance in patients stratified by baseline renal function.

Patients and methods: The OSPREY clinical trial enrolled 2 cohorts: A-high-risk patients undergoing radical prostatectomy with pelvic lymphadenectomy, and B-patients with suspected recurrent/metastatic prostate cancer on conventional imaging. Baseline estimated glomerular filtration rates were calculated, and patients were stratified by baseline chronic kidney disease (CKD) stage. Changes in serum creatinine within 28 days postdose and diagnostic performance of piflufolastat F-18 were assessed for each CKD stage group in both cohorts.

Results: 385 patients (cohort A, n = 268; cohort B, n = 117) underwent piflufolastat F-18-PET/CT. Baseline and postpiflufolastat F-18 median creatinine levels (mg/dL) were similar for patients in cohort A (0.95 [n = 264] vs. 0.95 [n = 252], respectively) and cohort B (0.93 [n = 116] vs. 0.96 [n = 84], respectively). Among 332 men (cohort A, n = 249; cohort B, n = 83) with baseline and postpiflufolastat creatinine measurements, there were minimal changes in creatinine across all baseline CKD stage groups (median change ranged from -0.02 to 0.023 in groups with >1 patient). The diagnostic performance of piflufolastat F-18 showed no meaningful differences when stratified by baseline CKD stage.

Conclusion: Piflufolastat F-18 appears to be safe and effective for imaging prostate cancer, including men with mild/moderate renal insufficiency.