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CompletedNCT04519294Updated Feb 27, 2026Results posted

Comparison of Laser Lithotripsy With and Without Steerable Ureteroscopic Renal Evacuation (SURE)

An interventional study of SURE and Standard Ureteroscopy (Basketing) in Kidney Stone, Renal Stone and Urolithiasis, sponsored by Calyxo, Inc.. Completed at 11 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-27.

Sponsored by Calyxo, Inc. · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
132
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The purpose of the study is to compare the effects, good and/or bad, of a treatment for removing kidney stones called the SURE procedure for stone evacuation to the standard treatment using a basket for stone removal.

02

Conditions studied

  • Kidney Stone
  • Renal Stone
  • Urolithiasis
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Candidate for ureteroscopy with laser lithotripsy;
  • Presence of renal stone(s);
  • Be willing and able to return for all study-related follow up procedures; and,
  • Have been informed of the nature of the study, agreeing to its requirements, and have signed the IRB approved informed consent.

Exclusion criteria

Exclusion Criteria:

  • BMI > 45;
  • Significant comorbidities;
  • Bladder, ureteral or kidney abnormalities;
  • Pregnant individuals; or
  • Unable to meet the treatment and follow up protocol requirements.
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
132 participants (actual)

Study arms

  • Active comparator
    SURE

    Device: SURE

  • Active comparator
    Standard Ureteroscopy (Basketing)

    Device: Standard Ureteroscopy (Basketing)

Interventions

  • DeviceSURE

    The SURE stone evacuation procedure is a technique intended to more easily and completely remove a kidney stone during a kidney stone treatment. The urologist first uses a laser to break the kidney stone into small pieces. Then with the SURE procedure, the pieces are gently vacuumed out of the kidney instead of retrieving the pieces one-by-one with a basket or leaving them to pass naturally in the urine. Basketing is allowed and might be used with the SURE procedure, if needed to remove some small stones.

  • DeviceStandard Ureteroscopy (Basketing)

    This is a treatment in which the urologist uses a laser to break a kidney stone into small pieces and then uses a tool called a basket to retrieve the pieces one at a time.

05

What researchers measure

Primary outcomes

  1. Stone Free Rate (SFR) - Zero Fragments

    The primary efficacy endpoint is the SFR, where stone free status is defined as zero residual fragments at 30 days observed on non-contrast CT (NCCT) (1.25mm slice thickness) by blinded central reviewer(s). The SFR is calculated by determining the number of subjects in each treatment arm with a stone free status of zero fragments and dividing that by the total number of subjects treated in the respective treatment arm.

    Time frame: 30 Days

Secondary outcomes

  1. Residual Stone Volume (RSV)

    A continuous quantitative measure of remaining stone volume following intervention, assessed via post-procedural imaging on NCCT (1.25mm slice thickness) by blinded central reviewer(s).

    Time frame: 30 Days

  2. Stone Clearance (% Reduction in Stone Volume)

    Percent reduction (\[Baseline stone volume- 30-Day stone volume\] / Baseline stone volume) in stone volume following intervention, assessed via post-procedural imaging on NCCT (1.25mm slice thickness) by blinded central reviewer(s). A positive result indicates a decrease in stone volume removed during the procedure; a negative value indicates an increase in stone volume following the procedure.

    Time frame: 30 Days

06

Results

Posted Jan 27, 2026

Participant flow

Participant flow — Overall Study
MilestoneSUREStandard Ureteroscopy (Basketing)
Started4655
Completed4350
Not completed35

Outcome measures

PrimaryStone Free Rate (SFR) - Zero Fragments

The primary efficacy endpoint is the SFR, where stone free status is defined as zero residual fragments at 30 days observed on non-contrast CT (NCCT) (1.25mm slice thickness) by blinded central reviewer(s). The SFR is calculated by determining the number of subjects in each treatment arm with a stone free status of zero fragments and dividing that by the total number of subjects treated in the respective treatment arm.

Time frame:
30 Days
Reported as:
Number · % subjects
Stone Free Rate (SFR) - Zero Fragments
% subjectsSUREStandard Ureteroscopy (Basketing)
Stone Free Rate (SFR) - Zero Fragments4849
SecondaryResidual Stone Volume (RSV)

A continuous quantitative measure of remaining stone volume following intervention, assessed via post-procedural imaging on NCCT (1.25mm slice thickness) by blinded central reviewer(s).

Time frame:
30 Days
Reported as:
Mean · mm^3
Residual Stone Volume (RSV)
mm^3SUREStandard Ureteroscopy (Basketing)
Residual Stone Volume (RSV)14.3 ± 30.970.2 ± 144.9
SecondaryStone Clearance (% Reduction in Stone Volume)

Percent reduction (\[Baseline stone volume- 30-Day stone volume\] / Baseline stone volume) in stone volume following intervention, assessed via post-procedural imaging on NCCT (1.25mm slice thickness) by blinded central reviewer(s). A positive result indicates a decrease in stone volume removed during the procedure; a negative value indicates an increase in stone volume following the procedure.

Time frame:
30 Days
Reported as:
Mean · percent reduction (%)
Stone Clearance (% Reduction in Stone Volume)
percent reduction (%)SUREStandard Ureteroscopy (Basketing)
Stone Clearance (% Reduction in Stone Volume)97.1 ± 5.493.3 ± 11.7

Adverse events

Collected over 30 Day. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
SURE0/67 (0%)1/67 (1.5%)4/67 (6%)
Standard Ureteroscopy (Basketing)0/65 (0%)2/65 (3.1%)5/65 (7.7%)
Most frequent serious events
Most frequent serious events
EventSUREStandard Ureteroscopy (Basketing)
Sepsis Requiring HospitalizationRenal and urinary disorders1/672/65
Most frequent other events
Most frequent other events
EventSUREStandard Ureteroscopy (Basketing)
Ureteral DamageRenal and urinary disorders4/675/65

Baseline characteristics

Age, Customized
Age, Customized(years)SUREStandard Ureteroscopy (Basketing)Total
Age59 ± 1460 ± 1459 ± 13
Sex: Female, Male
Sex: Female, Male(Participants)SUREStandard Ureteroscopy (Basketing)Total
Female222749
Male242852
Race/Ethnicity, Customized
Race/Ethnicity, Customized(Participants)SUREStandard Ureteroscopy (Basketing)Total
White (Not Hispanic)364480
Black or African American257
Hispanic/Latino7613
Asian101
Total stone burden
Total stone burden(mm)SUREStandard Ureteroscopy (Basketing)Total
Mean14 ± 6.519 ± 1117 ± 9
Total stone volume
Total stone volume(mm^3)SUREStandard Ureteroscopy (Basketing)Total
Mean490 ± 430710 ± 560610 ± 510
07

Study locations

11 sites
  • Mayo Clinic
    Phoenix, Arizona 85054, United States
  • Arizona Institute of Urology
    Tucson, Arizona 85704, United States
  • Johns Hopkins
    Baltimore, Maryland 21287, United States
  • New Jersey Urology
    Voorhees Township, New Jersey 08043, United States
  • Albany Medical College
    Albany, New York 12208, United States
  • Duke University
    Durham, North Carolina 27710, United States
  • Prisma Health
    Greenville, South Carolina 29650, United States
  • Urology Austin
    Austin, Texas 78654, United States
  • Dell Medical School, The University of Texas at Austin
    Austin, Texas 78712, United States
  • UT Southwestern Medical Center
    Dallas, Texas 75390, United States
  • Urology of Virginia
    Virginia Beach, Virginia 23462, United States
08

References and documents

Study documents

  • Protocol and statistical analysis plan · Jan 26, 2023

Documents are hosted by the registry — open the source record to download them.

09

Registry details

Key details

Study ID
NCT04519294
Lead sponsor
Calyxo, Inc.
Responsible party
Sponsor
First posted
Aug 19, 2020
Start date
Jun 16, 2021
Primary completion
Jan 30, 2023
Completion
Apr 30, 2025
Results posted
Jan 27, 2026
Last update
Feb 27, 2026

Oversight

FDA-regulated drug
No
FDA-regulated device
Yes
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