Zenflow, Inc. has announced promising long-term data showing that its investigational Spring® System provides significant and durable benefits for benign prostatic hyperplasia (BPH) patients three years after placement. The results, presented at the 2025 Annual Meeting of the American Urological Association in Las Vegas, position the device as a frontrunner in the emerging First-Line Interventional Therapy (FIT) category.
The three-year data from the ZEST pilot studies demonstrated sustained symptom improvement, with patients experiencing a 46% reduction in International Prostate Symptom Score (IPSS) compared to baseline (11.8 vs. 22.0). Quality of life scores showed similar durability, with BPH's negative impact reduced by half (IPSS-QOL 2.23 vs. 4.49 at baseline).
Sustained Clinical Benefits with Preserved Sexual Function
The data revealed consistent effectiveness over time, with 74% of patients achieving clinically significant symptom improvement (defined as ≥30% IPSS reduction) at 36 months. This response rate remained stable compared to earlier timepoints (75% at 12 months and 70% at 24 months).
Importantly, the device maintained urinary flow improvements, with peak flow rate (Qmax) increasing to 13.9 mL/s from 10.6 mL/s at baseline. No deterioration in erectile or ejaculatory function was observed throughout the three-year follow-up period, addressing a common concern with traditional BPH treatments.
"It's exciting to see the front-runner in the FIT category continue to deliver consistent, long-term results for men living with BPH," said Dr. Dean Elterman, Associate Professor at the University of Toronto and an attending urologist at the University Health Network, who presented the research. "Zenflow is the first to demonstrate this level of durability, and the only device offering a range of lengths and diameters to provide a truly tailored therapy."
Dr. Elterman highlighted the absence of implant encrustation or migration as particularly significant safety advantages, calling the Zenflow Spring "a standout innovation in the field, and one to watch."
Bridging the Treatment Gap for BPH
BPH affects millions of men worldwide, causing urinary symptoms that significantly impact quality of life. Traditional treatment options range from medications with potential side effects to invasive surgical procedures. The Zenflow Spring System aims to fill the gap between these extremes.
The device works through a small spring-like coil that gently props open the urethra, restoring normal function while preserving natural anatomy. As a FIT intervention, it offers distinct safety advantages, including reversibility if needed.
"We're encouraged to see the three-year data build upon the strong efficacy and durability results we saw at two years," said Shreya Mehta, CEO of Zenflow. "This further underscores the Zenflow Spring as a promising, much-needed alternative for BPH patients and urologists seeking FIT options."
Robust Study Design and Future Directions
The ZEST pilot studies included 72 subjects who received the Zenflow Spring device. The research employed comprehensive assessment methods, measuring symptom improvement via IPSS and IPSS-QOL, functional improvement through peak urinary flow rate, and sexual health using validated questionnaires.
Overall effectiveness measures were calculated using a mixed model repeated measures (MMRM) analysis, which incorporates within-patient correlations and missing data, and equally weighs results from each study.
The safety and effectiveness of the Zenflow Spring System is currently being evaluated through BREEZE™, a large, multi-center, prospective randomized study in the United States and Canada. This pivotal trial will support the company's efforts toward FDA approval and commercial launch.
The Zenflow Spring System remains an investigational device not yet approved for commercial sale. However, these three-year results represent the longest-term data among FIT interventions, establishing an important benchmark for this emerging treatment category.
