Trial of Transurethral Bulking Agent Injection Versus Single-Incision Sling for Stress Urinary Incontinence (BASIS)

June 4, 2026 updated by: NICHD Pelvic Floor Disorders Network

A Randomized Trial of Transurethral Bulking Agent Injection Versus Single-Incision Sling for Stress Urinary Incontinence

This is a multicentered, double-blind, randomized controlled, surgical trial of 358 women with inadequate symptom relief of stress urinary incontinence (SUI) or stress predominant mixed urinary incontinence (MUI) after conservative care.

The Primary Aim is to determine the comparative effectiveness (as defined by "much" or "very much" better on PGI-I) of transurethral bulking agent (TBA) [for 1 or 2 injections in 12 months] vs. single-incision sling (SIS) 12 months after treatment intervention in women with predominant stress urinary incontinence (SUI).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The BASIS trial is a multicentered, double-blind, randomized controlled, surgical trial with two active interventions, 1) a transurethral bulking agent (TBA) or 2) a single-incision sling (SIS). Both interventions are FDA-approved treatment options for urinary incontinence and will be used in line with their approved use. Participants will be randomly assigned to one of the interventions. A total of 358 women will be randomized 1:1 to TBA or SIS.

All participants will have data including demographics, medical history, and quality of life assessments as they relate to urinary incontinence collected at baseline. After undergoing treatment (either transurethral bulking agent or single-incision sling), participants will be asked to return to the clinic at 2-4 weeks, 3 months, and 12 months with additional follow-ups at 6 months, 24 months, and 36 months done over the phone.

The primary outcome of the BASIS trial is subjective success measured by PGI-I for TBA vs. SIS at 12 months.

Secondary outcomes include assessments of 1) retreatment rates within 12 months; 2) validated, objective measures of condition improvement through 36 months; 3) objective success at 3 and 12 months as measured by standardized cough stress test; 4) functional outcomes (activity level, perceived recover, sexual function, etc.); 5) quality of life assessments; 6) operative procedure data and adverse events; 7) pain and functional activity, need for sedation and anesthesia, de novo or worsening symptoms; 8) medical resource use (additional medications, procedures, or therapies); and 9) healthy utility measures.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
358

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • La Jolla, California, United States, 92037-0974
        • Recruiting
        • University of California at San Diego
        • Principal Investigator:
          • Emily Lukacz, MD
        • Contact:
      • San Diego, California, United States, 92110
    • Illinois
      • Chicago, Illinois, United States, 60637
        • Recruiting
        • University of Chicago
        • Principal Investigator:
          • Kimberly Kenton, MD
        • Contact:
    • North Carolina
      • Durham, North Carolina, United States, 27707
        • Recruiting
        • Duke University, Duke Division of Urogynecology and Reconstructive Pelvic Surgery
        • Principal Investigator:
          • Nazema Siddiqui, MD
        • Contact:
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
    • Rhode Island
      • Providence, Rhode Island, United States, 02903
        • Recruiting
        • Brown/ Women and Infants Hospital of Rhode Island, Division of Urogynecology and Reconstructive Pelvic Surgery
        • Principal Investigator:
          • Vivian Sung, MD
        • Contact:
    • Texas
      • Dallas, Texas, United States, 75390
        • Recruiting
        • University of Texas Southwestern Medical Center
        • Principal Investigator:
          • David Rahn, MD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Women ≥ 21 years
  • For > 3 months, bothersome SUI (response of somewhat, moderately, or quite a bit) without UUI or stress-predominant MUI. For those with equal bother of UUI and SUI, clinician determination that SUI is more severe/significant than UUI is required.
  • A positive cough stress test on standardized non-invasive testing or urodynamic SUI within the past 18 months.
  • Normal PVR < 150 mL
  • Candidate for either study procedure as determined by treating surgeon
  • Available for up to 3 years.
  • Agrees to randomization.

Exclusion Criteria:

  • Anterior/apical vaginal prolapse beyond the hymen (>0 on POPQ)
  • Urge-predominant mixed UI despite stable therapy
  • Advanced UUI/OAB 3rd line therapy treatment within 1 year of enrollment.
  • Planned hysterectomy, urethral or anterior/apical surgeries s requiring general anesthesia at the time of SUI treatment, during the last 6 months, or planned within the next 12 months.
  • Malignancy or history of radiation of the pelvis
  • Pregnant, post-partum, breast feeding or plans for pregnancy within 1 year
  • Incomplete emptying (PVR > 150mL)
  • Prior anti-incontinence procedure
  • Neurogenic bladder
  • Unwilling to continue current UUI treatment until completion of primary outcome at 12 months
  • Prior adverse reaction to synthetic mesh or urethral bulking material
  • Chronic bladder or pelvic pain conditions (e.g., Interstitial cystitis, painful bladder syndrome, fibromyalgia, chronic pelvic pain, etc.)
  • Active treatment for SUI with a pessary. For those using a pessary or other SUI support device, a 3-week washout period should occur prior to assessing baseline measures.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Solyx Single-incision Sling
Device: Solyx Single-incision Sling
Minimally invasive mesh device placed to treat stress urinary incontinence.
Active Comparator: Bulkamid Transurethral Bulking Agent
Device: Bulkamid Transurethral Bulking Agent
Minimally invasive bulking agent injections used to bulk up the tissue surrounding the urethra to treat stress urinary incontinence. Up to 2 treatments within 12 months are allowed

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Subjective success measured by Patient Global Impression-Improvement [PGI-I] (>2) for TBA vs. SIS at 12 months.
Time Frame: At 12 months post-intervention.

The PGI-I is used to compare condition improvement, defined as (1) = very much better, (2) = much better, (3) = a little better, (4) = no change, (5) = a little worse, (6) much worse, (7) very much worse.

Determine the comparative effectiveness (as defined by "much" or "very much" improved on PGI-I) of transurethral bulking agent [for 1 or 2 injections in 12 months] vs. single-incision sling 12 months after treatment intervention in women with predominant stress urinary incontinence.
At 12 months post-intervention.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Rates of retreatment
Time Frame: From intervention to 12 months post-intervention.
Rates of additional, non-protocol treatments (including other medications, therapies, or medical procedures) for stress urinary incontinence within 12 months after the initial TBA vs. SIS including success rates after 1 vs 2 TBA injections.
From intervention to 12 months post-intervention.
Change in Incontinence Questionnaire-Urinary Incontinence Short Form [ICIQ-SF] score
Time Frame: From intervention to 36 months post-intervention.

The International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) consists of 3 scorable questions measuring frequency of leakage, volume of leakage, and associated bother with leakage, for a range of scores from 0 (no leakage or bother) to 21 (worst leakage, most bothersome). A fourth question asks which type(s) of leakage are occurring.

The ICIQ-SF score is collected at baseline and each follow-up time point up to 36 months according to treatment assignment and as treated.
From intervention to 36 months post-intervention.
Subjective success measured by Patient Global Impression-Improvement [PGI-I] (>2) for TBA vs. SIS
Time Frame: From 3 months to 36 months post-intervention.

The PGI-I is used to compare condition improvement, defined as (1) = very much better, (2) = much better, (3) = a little better, (4) = no change, (5) = a little worse, (6) much worse, (7) very much worse.

Determine the comparative effectiveness (as defined by "much" or "very much" improved on PGI-I) of transurethral bulking agent [for 1 or 2 injections in 12 months] vs. single-incision sling 12 months after treatment intervention in women with predominant stress urinary incontinence.

PGI-I at each follow up time point up to 36 months according to treatment assignment and as treated.
From 3 months to 36 months post-intervention.
Condition improvement measured by Patient Global Symptom Control [PGSC] for TBA vs. SIS
Time Frame: From interventions to 36 months post-intervention.

The Patient Global Symptom Control (PGSC) is a patient-reported measure of perceived agreement that symptoms are under control, as assessed on a scale of 1 (Disagree Strongly) to 5 (Agree Strongly). Included here are participants who had reported disagreements as indicated by a rating of 1 (Disagree Strongly) or 2 (Disagree)

PGSC is collected at baseline and each follow up time point up to 36 months according to treatment assignment and as treated.
From interventions to 36 months post-intervention.
Condition improvement measured by Patient Global Impression of Severity [PGI-S] for TBA vs. SIS
Time Frame: From intervention to 36 months post-intervention.

The Patient Global Impression of Severity (PGI-S) is a patient-reported measure of perceived severity of condition, as assessed on a scale of 1 (Normal) to 4 (Severe). The outcomes is calculated as those that reported Normal or Mild severity as indicated by a rating of 1 or 2.

PGI-S at baseline and each follow up time point up to 36 months according to treatment assignment and as treated.
From intervention to 36 months post-intervention.
Condition improvement measured by Urogenital Distress Inventory - Long Form [UDI-LF] for TBA vs. SIS
Time Frame: From intervention to 36 months post-intervention.

The Urogenital Distress Inventory (UDI) is a standardized a measure of overactive bladder symptoms and health-related quality of life. The UDI scale has a range from 0 to 300 with higher scores indicating greater distress.

UDI-LF is collected at baseline and each follow up time point up to 36 months according to treatment assignment and as treated.
From intervention to 36 months post-intervention.
Objective success by standardized cough testing
Time Frame: From 3 to 12 months post-intervention.
Objective success at 3 and 12 months after TBA (1 or 2 injections) vs. SIS by standardized cough testing with a minimum 300 mL bladder volume. (Note, objective failure may be present below 300 mL)
From 3 to 12 months post-intervention.
New or worsening urge incontinence function
Time Frame: From intervention to 36 months post-intervention.
Number of participants with new or worsening onset urge urinary incontinence (UUI) (including need for additional or change in UUI treatment in those on UUI therapy at baseline)
From intervention to 36 months post-intervention.
Sexual functional measured by the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire, IUGA-Revised [PISQ-IR] for TBA vs. SIS
Time Frame: From intervention to 36 months post-intervention.

The Pelvic Organ Prolapse Incontinence Sexual Questionnaire, IUGA-revised measures the impact of incontinence symptoms on sexual function and satisfaction. The Sexually Active-Average (SA-AVG) ranges from 1 to 5 with higher scores indicating greater sexual function.

PISQ-IR is collected at baseline and each follow up time point up to 36 months according to treatment assignment and as treated.
From intervention to 36 months post-intervention.
Quality of life improvement measured by Incontinence Impact Questionnaire - Long Form [IIQ-LF] for TBA vs. SIS
Time Frame: From baseline to 36 months post-intervention.

The Incontinence Impact Questionnaire-Long Form is a standardized a measure of health-related quality of life. The IIQ-LF Total score ranges from 0 to 400 with higher scores indicating worse impact.

IIQ-LF is collected at baseline and each follow up time point up to 36 months according to treatment assignment and as treated.
From baseline to 36 months post-intervention.
Quality of life improvement measured by 36-Item Short Form Health Survey [SF-36] for TBA vs. SIS
Time Frame: From baseline to 36 months post-intervention.

The SF-36 determines participants' overall quality of life by assessing 1. limitations in physical functioning due to health problems; 2. limitations in usual role because of physical health problems; 3. bodily pain; 4. general health perceptions; 5. vitality; 6. limitations in social functioning because of physical or emotional problems; 7. limitations in usual role due to emotional problems; and 8. general mental health. Scores range from 0 to 100 with higher scores indicating better quality of life.

SF-36 is collected at baseline and each follow up time point up to 36 months according to treatment assignment and as treated.
From baseline to 36 months post-intervention.
Quality of life improvement measured by Decision Regret Scale- Satisfaction with Decision Scale [DRS-SDS] for TBA vs. SIS
Time Frame: From baseline to 36 months post-intervention.

The DRS-SDS is a standardized assessment of treatment satisfaction. It asks subjects to reflect on a particular decision and then rate each item on a Likert scale from 1 (strongly agree) to 5 (strongly disagree). Higher scores are worse.

DRS-SDS at baseline and each follow up time point up to 36 months according to treatment assignment and as treated.
From baseline to 36 months post-intervention.
Blood Loss
Time Frame: At intervention
Estimated quantity of blood lost during protocol procedures.
At intervention
Operative time
Time Frame: At intervention
Estimated total time of operative procedure
At intervention
Operative Procedure-related adverse events
Time Frame: At intervention
Number of participants with intra- and post-operative complications requiring treatment or any treatment for voiding dysfunction or pain, categorized using a modification of the Dindo Classification.
At intervention
Post-op pain
Time Frame: Between 3 and 12 months post-intervention
Number of participants with de novo or worsening pelvic floor muscle tenderness or de novo or worsening dyspareunia or surgical pain between 3 and 12 months
Between 3 and 12 months post-intervention
Intraoperative Pain management
Time Frame: At intervention
Number of participants with intraoperative need for additional sedation or anesthesia beyond local injection.
At intervention
Functional activity measured by Activity Assessment Scale [AAS] for TBA vs. SIS
Time Frame: From intervention to 36 months post-intervention.

The AAS is a is a standardized a measure of impact of incontinence on normal and more strenuous activities. The score ranges from 0 to 100 with higher scores indicating greater functional activity.

AAS is collected at at baseline and each follow up time point up to 36 months according to treatment assignment and as treated.
From intervention to 36 months post-intervention.
Medical resource use
Time Frame: From intervention to 36 months post-intervention.
The number of participants with new medications, new symptoms or complaints, life events, and intercurrent therapies for incontinence and other urinary symptoms, intercurrent complications from treatment, intercurrent therapies for complications.
From intervention to 36 months post-intervention.
Medical Resource Cost
Time Frame: From intervention to 36 months post-intervention.
The estimated direct and indirect cost of the intervention, new medications, new symptoms or complaints, life events, and intercurrent therapies for incontinence and other urinary symptoms, intercurrent complications from treatment, intercurrent therapies for complications.
From intervention to 36 months post-intervention.
Health utility measure measured by the European Quality of Life-5 Dimensions (EQ-5D-5L)
Time Frame: From baseline to 36 months post-intervention.

European Quality of Life-5 Dimensions (EQ-5D-5L) is a standardized instrument developed by the EuroQol Group as a measure of health-related quality of life. The EQ-5D-5L has 5 attributes (mobility, self-care, usual activities, pain/discomfort and anxiety/depression).

EQ-5D descriptive system is divided into five levels of perceived problems:

LEVEL 1: indicating no problem LEVEL 2: indicating slight problems LEVEL 3: indicating moderate problems LEVEL 4: indicating severe problems LEVEL 5: indicating unable to/extreme problems
From baseline to 36 months post-intervention.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
NICHD Pelvic Floor Disorders Network

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
University of Pennsylvania
University of California, San Diego
University of Chicago
Duke University
University of Texas Southwestern Medical Center
Kaiser Permanente
Women and Infants Hospital of Rhode Island
RTI International

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Emily Lukacz, MD, University of California, San Diego
  • Principal Investigator: Marie Gantz, MD, RTI International

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 28, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2030

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 14, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 24, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 28, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PFDN-33P01
  • UG1HD069013 (U.S. NIH Grant/Contract)
  • UG1HD054214 (U.S. NIH Grant/Contract)
  • UG1HD041267 (U.S. NIH Grant/Contract)
  • UG1HD054241 (U.S. NIH Grant/Contract)
  • UG1HD110057 (U.S. NIH Grant/Contract)
  • UG1HD069010 (U.S. NIH Grant/Contract)
  • U24HD069031 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Study data will be made available through DASH

IPD Sharing Time Frame

Plan to submit full study dataset before the end of the award period.

IPD Sharing Access Criteria

Access is managed by DASH.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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