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NCT Number: NCT07797348

Prospective Post Market Clinical Trial for the Zenflow Spring System - A Minimally Invasive Treatment for LUTS Associated With BPH.

This is a prospective, randomized, open-label, parallel-group post-market clinical trial (PMCT). The overall objective of this PMCT is to compare the effectiveness, durability, and patient-centered outcomes of the Zenflow Spring System versus Tamsulosin in men who are not on active therapy with moderate to severe LUTS/BPH. Patients randomized to the Tamsulosin therapy arm will be allowed to crossover to receive treatment with the Zenflow Spring System after 1) their 3-month follow-up assessments are completed, 2) the patient's symptoms are confirmed to continue to warrant treatment; and 3) the patient continues to meet the study enrollment criteria.

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Key information

Conditions

Benign Prostatic Hyperplasia (BPH) Enlarged Prostate Genital Diseases Genital Diseases, Male Male Urogenital Diseases Obstructive Lower Urinary Tract Symptoms (LUTS) Prostatic Diseases Prostatic Hyperplasia Urogenital Diseases

Age range

18 year and older

Sex eligibility

Male

Study type

Interventional

Phase

Phase 4

About this study

The purpose of this post-market clinical trial (PMCT) is to compare the Zenflow Spring System with Tamsulosin in men with moderate to severe BPH symptoms who are not currently receiving treatment.

The study will look at how well each treatment works, how long the results last, how quickly patients return to normal activities, how satisfied they are with their treatment, and any side effects. Patients will be followed at 1, 3, 6, and 12 months. The study will also track any implant removals or additional procedures, as well as any changes to or stopping of Tamsulosin.

Patients who qualify for the study will be randomly assigned, with an equal chance, to receive either the Zenflow Spring System or Tamsulosin.

Patients randomized to the Tamsulosin therapy arm will be allowed to crossover to receive treatment with the Zenflow Spring System after 1) their 3-month follow-up assessments are completed, 2) the patient's symptoms are confirmed to continue to warrant treatment; and 3) the patient continues to meet the study enrollment criteria. No crossover will be permitted beyond 30 days after completion of the 12-month follow-up. Patients who elect crossover and have a successful placement of the Spring Implant will be followed for 1 additional month and then will exit the study.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

The Spring® Implant and Delivery System is indicated for the treatment of obstructive lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH) in men with prostatic urethral lengths between 25mm and 45mm and prostate sizes between 25cc and 80cc.

In addition to the above labeling requirements, patients must also meet all the following criteria to be eligible for enrollment in this study:

  • Moderate to severe LUTS, defined as an International Prostate Symptom Score (IPSS ≥ 8)
  • Not actively taking any medication indicated for BPH, defined as current use of:
  • Alpha-adrenergic antagonists (Alpha Blockers) within 2 weeks of baseline IPSS assessment
  • 5-alpha reductase inhibitors (5ARI) within 6 months of baseline IPSS assessment
  • PDE5 daily use (on demand use is permitted)
  • Ability to provide informed consent and comply with study procedures and follow-up schedule

Exclusion criteria

  • Known, previous adverse reaction to use of alpha-adrenergic antagonists (e.g., Tamsulosin)
  • Neurologic conditions affecting bladder function, including but not limited to:
  • Multiple sclerosis
  • Parkinson's disease
  • Neurogenic bladder or other conditions causing non-obstructive voiding dysfunction

Treatment and study plan

Zenflow Arm: Zenflow Spring System implant procedure

Device

The Zenflow Spring Implant is designed to be a permanent implant but can be repositioned or removed by the physician.

Medical Therapy Tamsulosin

Drug

Tamsulosin is a prescription medicine that relaxes the muscles around the prostate and bladder to help men with an enlarged prostate (BPH) urinate more easily

Primary outcomes

  1. International Prostate Symptom Score (IPSS) Total Score

    Time frame: Baseline (Day 1) to 3 months

    Mean change in IPSS Total Score from baseline at 3 months. This is a 7-question patient questionnaire used to measure the severity of lower urinary tract symptoms associated with BPH. Each of the 7 symptom questions is scored from 0 to 5, giving a total possible score of 0-35. Lower scores are better.

  2. Observed rate of device-related or Tamsulosin-related serious adverse events (SAEs).

    Time frame: Baseline through study completion, an average of 1 year (Duration of study)

    Observed rate of device-related or Tamsulosin-related serious adverse events (SAEs).

Secondary outcomes

  1. Mean change in International Prostate Symptom Score (IPSS) Total Score from baseline at 1, 6, and 12 months

    Time frame: Baseline at 1, 6, and 12 months

    Mean change in International Prostate Symptom Score (IPSS) Total Score from baseline at 1, 6, and 12 months. This is a 7-question questionnaire used to measure the severity of lower urinary tract symptoms associated with BPH. Each of the 7 symptom questions is scored from 0 to 5, giving a total possible score of 0-35. Lower scores are better

  2. Mean change in International Prostate Symptom Score (IPSS) Quality of Life (QoL) from baseline 1, 3, 6 and 12 months

    Time frame: Baseline 1, 3, 6 and 12 months

    Mean change in International Prostate Symptom Score (IPSS) Quality of Life (QoL) from baseline 1, 3, 6 and 12 months. This separate Quality of Life (QoL) question, scored 0-6, is asking how the patient would feel if they had to live with their current urinary condition for the rest of their life. The QoL score is reported separately and is not included in the 0-35 IPSS total

  3. Adherence to assigned treatment (Spring Implant arm or Medical Therapy Arm) and reasons for any discontinuations

    Time frame: Baseline through study completion, an average of 1 year (Study duration)

    In the Spring Implant arm, the patient will be asked if they remain implanted with the Spring Implant and if since last visit, if patient initiated any concomitant BPH medication use (for > 2 weeks). In the Medical Therapy Arm the patient will be asked since last visit, to confirm if they have been consistently taking Tamsulosin at the required dose.

  4. The observed rates of device related AEs or Tamsulosin-related adverse events

    Time frame: Baseline through study completion, an average of 1 year (Duration of study)

    The observed rates of device related AEs or Tamsulosin-related adverse events

Sponsors and collaborators

Lead sponsor

Zenflow, Inc.

Industry

Registry information

Official study title

Prospective Post Market Clinical Trial for the Zenflow Spring System - A Minimally Invasive Treatment for LUTS Associated With BPH

Important dates

Study start
2026
Primary completion
2028
Study completion
2029
First posted
Sep 1, 2026
Registry last updated
Sep 1, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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