ROBUST I Pilot Study, Re-Establishing Flow Via Drug Coated Balloon For The Treatment Of Urethral Stricture Disease

The study is designed to determine the safety and effectiveness for drug coated balloon (DCB).

Up to 50 subjects is planned to be enrolled and treated with the study device at up to 5 clinical sites outside of US. Due to significantly higher prevalence of strictures in men vs. women and the etiology of those strictures being different, the study will focus on male subjects with single anterior urethral stricture. Subjects will be followed up post-treatment to one year and then annually for up to 5 years. The annual follow up after the first year is optional.

• Urotronic Drug Coated Balloon (DCB) (Combination product): Urotronic Drug Coated Balloon (DCB) is a catheter with a tapered atraumatic tip. The distal end of the catheter has a semi-compliant inflatable balloon coated with a proprietary coating containing the drug and carriers.

Primary outcomes

• Rate of Treatment Related Serious Complication [90 days post-procedure]: * urethral formation of fistula * de novo severe urinary retention lasting > 14 consecutive days' post-treatment * unresolved de novo stress urinary incontinence (requiring >1 pad/day) at 90 days or earlier * urethra rupture or burst.

Secondary outcomes

• Stricture Recurrence Rate [90 days post-procedure]: * IPSS score of greater than 11 at the 90-day follow-up, or * if a subject had a second DCB treatment (retreatment), or * if a subject exited the study early due to treatment failure (IPSS >11 without cystoscopically confirmed anatomical success at the time of exit or receiving additional stricture treatment with an alternative therapy).

Sex: Male, ages: 18 Years to any

Inclusion Criteria:

1. Male subjects ≥ 18 years' old
2. Visual confirmation of stricture via cystoscopy or urethrogram
3. Single lesion anterior urethral stricture or bladder neck contracture, less than or equal to 2.0 cm
4. One to three (1-3) prior diagnosis and treatment of the same stricture (including self-catheterization) including DVIU (Direct Vision Internal Urethrotomy), but no prior urethroplasty
5. Significant symptoms of stricture such as frequency of urination, dysuria, urgency, hematuria, slow flow, feeling of incomplete emptying, recurrent UTI's.
6. IPSS score of 13 or higher
7. Lumen diameter <12F by urethrogram
8. Able to complete validated questionnaire independently
9. Qmax <10 ml/sec

Exclusion Criteria:

1. Strictures greater than 2.0 cm long.
2. Subjects that have more than 1 stricture.
3. Sensitivity to paclitaxel or on medication that may have negative interaction with paclitaxel
4. Subjects who have a suprapubic catheter and are unable to complete study required testing, such as uroflowmetry
5. Previous urethroplasty within the anterior urethra
6. Stricture due to bacterial urethritis or untreated gonorrhea
7. Stricture dilated or incised within the last 3 months
8. Presence of local adverse factors, including abnormal prostate making catheterization difficult, urethral false passage or fistula.
9. Presence of signs of obstructive voiding symptoms not directly attributable to the stricture such as BPH at the discretion of the clinical investigator
10. Previous radical prostatectomy
11. Previous pelvic radiation
12. Diagnosed kidney, bladder, urethral or ureteral stones or active stone passage in the past 6 months.
13. Diagnosed with chronic renal failure unless under hemodialysis or has a serum creatinine level greater than 2 mg/dL
14. Use of alpha blockers, beta blockers, OAB (Overactive Bladder) medication, anticonvulsants (drugs that prevent or reduce the severity and frequency of seizures), and antispasmodics where the dose is not stable. (Stable dose is defined as having the same medication and dose in the last six months.)
15. Use of Botox (onabotulinumtoxinA) in urinary system within the last 12 months

Participant flow

Outcome results

• Rate of Treatment Related Serious Complication (Primary), Number, percentage of participants: DCB Treatment 0 (0.0 to 6.7)
• Stricture Recurrence Rate (Secondary), Count of participants, Participants: DCB Treatment 8 (p <0.001)

Adverse events

Time frame: Adverse events were collected any time after the treatment has been initated through 5-year follow-up

Serious adverse events by term

Other adverse events by term

• Results publication: DeLong J, Virasoro R, Pichardo M, Estrella R, Rodriguez Lay R, Espino G, Elliott S. Long-Term Outcomes of Recurrent Bulbar Urethral Stricture Treatment With the Optilume Drug-Coated Balloon: Five-Year Results From the ROBUST I Study. J Urol. 2025 Jan;213(1):90-98. doi: 10.1097/JU.0000000000004229. Epub 2024 Aug 30. PMID 39213367

• Study Protocol (PDF, 2017-08-11)
• Statistical Analysis Plan (PDF, 2017-08-11)

• Ian Schorn, Study director, Urotronic (Study Sponsor)