Imaging Efficacy of [18F]CTT1057 PET/CT in Patients with Biochemically Recurrent Prostate Cancer: Results from GuidePath-A Phase 3, Prospective Multicenter Study
Por:
Fanti, S, Barba, JJR, Behr, S, Maurer, T, Paredes, P, Walz, J, Duch, J, Perdigo, MS, Mainta, IC, Bonnefoy, PB, Coulanges, M, Tang, J, Seigne, C, Wilke, C, Catafau, AM, Iagaru, A, Aggarwal, R
Publicada:
1 ago 2025
Resumen:
Improved diagnostic accuracy in patients with prostate cancer at first biochemical recurrence (BCR) with low prostate-specific antigen (PSA) levels is needed. This prospective study (GuidePath; NCT04838613) aimed to evaluate the imaging performance of the prostate-specific membrane antigen (PSMA)-targeted PET radiotracer [18F]CTT1057 to detect PSMA-positive lesions in patients diagnosed predominantly at first BCR. Methods: Eligible patients had a PSA of 0.2 ng/mL or greater after radical prostatectomy or an increase in PSA level of at least 2 ng/mL above nadir after radiation therapy. Patients received 370 MBq of [18F]CTT1057 and 150 MBq of [68Ga]Ga-PSMA-11 and underwent PET/CT 90 min (630 min) and 50-100 after injection, respectively. [18F]CTT1057 images were assessed by 3 independent readers blinded to all clinical information. Coprimary endpoints were region-level correct localization rate (CLR) and patient-level positive predictive value (PPV) of [18F]CTT1057 to detect PSMA-positive lesions and were compared with a hierarchical composite truth standard (CTS). The CTS comprised 3 levels of standard-of-truth procedures (in order of priority): histopathology (CTS level 1); imaging, including at least 1 contrast-enhanced CT scan and 1 [68Ga]Ga-PSMA-11 PET/CT scan (CTS level 2); and a decrease in PSA level of 50% or greater 3 mo after radiation therapy (CTS level 3). For study success, the lower-bound 95% CI had to surpass 50% for region-level CLR and 20% for patient-level PPV for at least 2 of the 3 [18F]CTT1057 PET/CT readers. Results: Of 202 patients screened, 161 were evaluable for efficacy. Among these, 93.2% were experiencing their first BCR, 96.3% had received radical prostatectomy as initial definitive therapy, and baseline median PSA level was 0.4 ng/mL (interquartile range, 0.3-0.8 ng/mL). The imaging standard of truth was used for 159-160 patients (99%) across the 3 readers. Both coprimary endpoints were met. Region-level CLR ranged from 65.2% to 75.0% (lower-bound 95% CI, 53.4%-62.1%), and patient-level PPV ranged from 64.6% to 76.5% (lower-bound 95% CI, 51.8%-62.5%). Conclusion: [18F]CTT1057 met the predefined thresholds for region-level CLR and patient-level PPV in a clinically relevant patient cohort predominantly at first BCR with low PSA levels. [18F]CTT1057 is an accurate PSMA-targeted PET radiotracer for BCR detection.
Filiaciones:
Fanti, S:
IRCCS AOU Bologna, Nucl Med, Bologna, Italy
Barba, JJR:
Hosp Univ Bellvitge, Nucl Med, Barcelona, Spain
Behr, S:
Univ Calif San Francisco, San Francisco, CA USA
Maurer, T:
Univ Hamburg Eppendorf, Dept Urol, Hamburg, Germany
Univ Hamburg Eppendorf, Martini Klin Prostate Canc Ctr, Hamburg, Germany
Paredes, P:
Univ Barcelona, Clin Hosp Barcelona, Inst Invest Biomed August Pi & Sunyer, Barcelona, Spain
Walz, J:
Calmettes Canc Ctr, Inst Paoli, Dept Urol, Marseille, France
Duch, J:
Hosp Santa Creu & Sant Pau, Dept Urol, Barcelona, Spain
Perdigo, MS:
Hosp Univ Vall Hebron, Barcelona, Spain
Mainta, IC:
Univ Geneva, Geneva Univ Hosp, Diagnost Dept, Div Nucl Med, Geneva, Switzerland
Bonnefoy, PB:
CHU St Etienne, Serv Med Nucleaire, St Etienne, France
Coulanges, M:
Novartis Co, Adv Accelerator Applicat, Geneva, Switzerland
Tang, J:
Novartis Pharmaceut, Biostat, E Hanover, NJ USA
Seigne, C:
Novartis Pharm AG, Basel, Switzerland
Wilke, C:
Novartis Pharm AG, Basel, Switzerland
Catafau, AM:
Novartis Co, Adv Accelerator Applicat, Geneva, Switzerland
Iagaru, A:
Stanford Univ, Stanford, CA USA
Aggarwal, R:
Univ Calif San Francisco, San Francisco, CA USA
Green Submitted, hybrid
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