Klotz, Laurence

369 Background: MRI-guided transurethral ultrasound ablation (TULSA) uses MRI to target, monitor, and control thermal ablation of prostate tissue with high intensity directional ultrasound, demonstrating favorable histologic control and preservation of genitourinary function in single-arm studies [1,2]. CAPTAIN (NCT05027477) is a post-market, multi-center randomized controlled trial (RCT) of TULSA vs RARP for intermediate-risk prostate cancer, and is the first such study to meet its enrolment target. Here we compare baseline patient characteristics, treatment parameters, and periprocedural outcomes. Methods: CAPTAIN enrolled men with treatment-naïve, organ-confined, Grade Group 2 or 3 prostate cancer at 23 centers including academic and private clinics in the USA (20), Canada (2), and Finland (1). Patients were randomized 2:1 to TULSA or RARP, without crossover. Endpoints include pad-free urinary continence (EPIC) and erections sufficient for penetration (IIEF Q2) at 1 year, salvage treatment at 3 years, and survival to 10 years. Periprocedural metrics include length of stay, blood loss, catheter time, and 30-day patient diary (EQ-5D-5L, NRS pain score). Results: 211 patients were treated from Jan 2022 to Aug 2025 (70% TULSA, 30% RARP), surpassing the enrolment target of 201. Arms had similar baseline characteristics: median (IQR) age for TULSA vs. RARP was 63 (58–68) vs 65 (60–69) years (p=0.12), PSA was 6.5 (4.9–9.6) vs 7.2 (5.6–9.7) ng/mL (p=0.63), Grade Group 2/3 proportions were 76%/24% vs 77%/23% (p=0.88). RARP involved bilateral, unilateral, or no nerve sparing in 89%, 5.7%, and 5.7% of cases. TULSA ablation plans included whole-gland (68%) and ≥hemi-ablation (32%). Median (IQR) blood loss was lower during TULSA vs RARP: 0 (0–0) vs 100 (100–200) mL (p<0.001). Hospital stay was shorter for TULSA: 0.29 (0.27–0.32) vs 1.24 (1.12–1.36) days (p<0.001). Catheter duration was longer post-TULSA: 13 (11–15) vs 8 (8–10) days (p<0.001). Patients reported lower NRS pain scores after TULSA to post-operative day 6, and less decline in overall health on the EQ-5D-5L 0-100 visual analog scale over 30 days (p<0.05). Fewer patients reported extreme inability on EQ-5D-5L after TULSA vs RARP over the first month for mobility (0% vs 15%), self-care (1% vs 18%), and usual activities (18% vs 38%) (all p<0.05). Conclusions: CAPTAIN is the first multicenter RCT comparing ablation to radical prostate cancer treatment to meet its enrollment target. Early perioperative results from CAPTAIN demonstrate that TULSA had no blood loss or overnight hospitalization, reduced post-procedural pain, and faster return to baseline activities and overall health. Data collection to 1 and 3 years post-treatment continues to readout of the primary safety and oncological outcomes. [1] Klotz et al 2021, JUrol 205(3):769-779. [2] Eggener et al 2024, UrolOnc 42:S83. Clinical trial information: NCT05027477 .

14046 Background: LDM CTX is a minimally toxic anti-angiogenic therapy that has demonstrated activity in multiple tumour types including HRPC. Increased Cyclooxygenase 2 (COX 2, a prostaglandin synthase enzyme) expression appears to be a consistent feature of a variety of human tumours, including prostate cancer. COX 2 inhibitors like CEL exhibit anti-tumour activity in pre-clinical studies, at least in part due to their anti-angiogenic activity. Pre-clinical work supports the concept that the combination of selective angiogenesis inhibitors like CEL with metronomic chemotherapy can enhance the effects of these agents on tumour angiogenesis. Methods: Men with asymptomatic HRPC at a single Canadian centre received celecoxib 400 mg po BID and cyclophosphamide 50 mg po daily. The primary efficacy endpoint of this 2 stage phase II study is disease control rate (DCR): 50% PSA response, tumour response or prolonged (=6 mos) PSA or stable measurable disease. This study is also assessing the safety of LDM CTX and CEL as well as potential anti-angiogenic biomarkers in these patients including circulating endothelial cells and their precursors (CEC/P), plasma levels of thrombospondin-1 (TSP-1) and vascular endothelial growth factor (VEGF). Results: Enrollment for the first stage of this study (10 men) has been completed. There were 2 patients with disease control by the a priori criteria: one patient with a partial tumour response (PR) (PR duration 13 mos with PSA stabilization for 12 mos) and one patient that had both prolonged stable PSA (7 mos) and prolonged stable measurable disease (8 mos). In addition, another patient had an unconfirmed PR. The therapy was well tolerated. One patient had angina that responded well to medical therapy but there were no serious arterial-thromboembolic events. One patient developed grade 3 hypertension. All other toxicities were grade 1/2. Data on CEC/P, TSP-1 and VEGF levels will be presented at the meeting. Conclusions: LDM CTX + CEL is a well tolerated therapy in men with asymptomatic HRPC. 2/10 patients achieved disease control in the first stage of the trial, meeting the criteria to proceed to the second stage. [Table: see text]