Phase 3 study of ⁶⁸ Ga-PSMA-11 PET combined with MRI for the detection of prostate cancer (BIPASS).

Abstract

TPS406 Background: Prostate cancer (PC) is diagnosed through directed & template/anatomical biopsy based on clinical and radiographic suspicion. In patients with high risk of PC, directed biopsies are performed to identify occult disease, which can lead to anxiety, complications, financial burden, & logistical challenges. PSMA PET combined with MRI for targeted biopsy may improve the detection of clinically significant PC (csPC) & treatment management, minimize cost and procedural risk, de-escalate the number of biopsies, & potentially eliminate the need for biopsies in select populations. In a study of 56 patients with PI-RADS 3 lesions, csPC was detected in only 8 patients (14.3%) by biopsy. When a PRIMARY score of ≥4 was used to make a biopsy decision in men with PI-RADS 3 lesions, 40/48 (83.3%) patients could have avoided unnecessary biopsies. Biopsy of the Prostate Avoidance Stratification Study (BIPASS) is evaluating the diagnostic performance of combining 68 Ga-PSMA-11 PET & MRI targeted biopsy for detection of PC, using histopathological confirmation as standard of truth (SOT). Methods: This Phase 3, single-arm, multicenter, prospective, open-label, longitudinal study (NCT07052214) will enroll 204 patients ≥18 years with clinical suspicion of PC are prostate biopsy naïve & scheduled to undergo template biopsy based on initial MRI within 3 months before enrollment (PI-RADS 1-4). Key exclusion criteria include prior treatment of PC, diagnosis of PC, or obvious metastatic disease on prior conventional imaging. Patients will undergo 68 Ga-PSMA-11 & MRI scans, followed by standard template biopsy. PSMA & MRI scans will be independently interpreted by 3 blinded readers. MRI- & PSMA-targeted biopsies will be performed with 2 cores per lesion. If PC is histopathologically identified, lesion linking with imaging will be performed with no further follow-up required. Follow-up data will be collected for up to 6m for patients with no baseline imaging or histopathological evidence of PC. Additional imaging & biopsies may be performed during the follow-up period at discretion of the investigator. Any additional biopsy, imaging, clinical, histological, genetic, & intervention data will contribute to the determination of SOT. Follow-up will provide longitudinal surveillance to ensure that patients initially evaluated as negative for PC on both imaging & histopathology are reliably negative. The co-primary endpoints are sensitivity & specificity of combining PSMA PET- and MRI- targeted biopsy for the detection of PC, calculated by comparing diagnostic findings to histopathological or composite SOT. Key secondary endpoints include detection performance (sensitivity, specificity, PPV, NPV, accuracy, & misclassification rate) of PSMA PET- & MRI- targeted biopsy for detection of PC and interobserver variability of PSMA PET interpretation. This study is open for enrollment & is sponsored by Telix Pharmaceuticals. Clinical trial information: NCT07052214 .