A Phase 4 interventional study of Zenflow Arm: Zenflow Spring System implant procedure and Medical Therapy Tamsulosin in Benign Prostatic Hyperplasia (BPH), Obstructive Lower Urinary Tract Symptoms (LUTS) and Enlarged Prostate, sponsored by Zenflow, Inc.. Not yet recruiting. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-01.
Sponsored by Zenflow, Inc. · Phase 4, Interventional, and Treatment
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.
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.
827 studies on the registry are indexed under Prostatic Hyperplasia; 179 are open to participants now.
This study's planned enrollment of 110 is above the median of 92 across 626 interventional studies indexed under Prostatic Hyperplasia.
Browse Prostatic Hyperplasia studies →Zenflow, Inc. is the lead sponsor of 7 studies on the registry; 3 are open to participants now.
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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:
Not actively taking any medication indicated for BPH, defined as current use of:
Exclusion Criteria:
Neurologic conditions affecting bladder function, including but not limited to:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Zenflow Arm: Patients randomized to the Zenflow Spring System arm will undergo the procedure according to manufacturer specifications and standardized procedural protocols.
Device: Zenflow Arm: Zenflow Spring System implant procedure
Medical Therapy Arm: Patients randomized to the medical therapy arm will receive Tamsulosin 0.4 mg once daily. Subjects will be encouraged to remain on this medical therapy through at least 3 months of treatment, unless significant adverse health reaction occurs.
Drug: Medical Therapy Tamsulosin
The Zenflow Spring Implant is designed to be a permanent implant but can be repositioned or removed by the physician.
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
International Prostate Symptom Score (IPSS) Total Score
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.
Time frame: Baseline (Day 1) to 3 months
Observed rate of device-related or Tamsulosin-related serious adverse events (SAEs).
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)
Mean change in International Prostate Symptom Score (IPSS) Total Score from 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
Time frame: Baseline at 1, 6, and 12 months
Mean change in International Prostate Symptom Score (IPSS) Quality of Life (QoL) from 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
Time frame: Baseline 1, 3, 6 and 12 months
Adherence to assigned treatment (Spring Implant arm or Medical Therapy Arm) and reasons for any discontinuations
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.
Time frame: Baseline through study completion, an average of 1 year (Study duration)
The observed rates of device related AEs or Tamsulosin-related adverse events
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)
No study locations are listed for this record.
Plan to share: Undecided
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Zenflow, Inc.