|
General |
Study Status |
Completed |
Application Number / Requirement Number |
P970004 S022/ PAS003 |
Date Original Protocol Accepted |
09/24/2002
|
Date Current Protocol Accepted |
04/02/2010
|
Study Name |
Single Tined Lead (protocol 1634)
|
Device Name |
INTERSTIM THERAPY FOR URINARY CONTROL
|
General Study Protocol Parameters |
Study Design |
Randomized Clinical Trial
|
Data Source |
New Data Collection
|
Comparison Group |
Concurrent Control
|
Analysis Type |
Analytical
|
Study Population |
Adult: >21
|
Detailed Study Protocol Parameters |
Study Objectives |
Prospective, multicenter Phase I -randomized trial Phase II- non-randomized
|
Study Population |
Phase I: Subjects enrolled and randomized either to InterStim Therapy (without OAB medications) or to Standard Medical Therapy and followed for # months. At month #, subjects in the Standard Medical Therapy group may undergo test stimulation and if successful receive the InterStim device.
Phase II: A sufficient number of additional subjects will be enrolled and not randomized. They will undergo test stimulation and if successful will receive the InterStim device in order to meet long-term follow-up sample size requirement.
|
Sample Size |
Phase I: # (#) will be randomized.
Phase II: # subjects receiving full implant for # year endpoint
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Key Study Endpoints |
Efficacy: At least # improvement in average voids/day from baseline or a return to normal voiding frequency (#) for subjects with urinary frequency at baseline. At lease # improvement in average leaks/day from baseline for subjects with urinary incontinence at baseline. Subjects with both frequency and incontinence at baseline must meet at least one of the above criteria to be considered a success.
Safety: Demonstrate that the upper bound of the #CI for the cumulative five-year rate of adverse events related to tined lead that require surgery after a full system implant is less than #.
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Follow-up Visits and Length of Follow-up |
5 years After full-system implant, follow-up visits will be completed for subjects at months 3, 6, 12, 24, 36, 48, and 60 months. For subjects randomized to InterStim who fail test stimulation will be followed for # months. Subjects in Phase II who fail test stimulation will be exited from the study.
|
Interim or Final Data Summary |
Actual Number of Patients Enrolled |
571 subjects were enrolled in the study, 272 subjects were implanted with the full system, and 169 had 5year data.
|
Actual Number of Sites Enrolled |
38 sites
|
Patient Follow-up Rate |
62% (169/272)
|
Final Safety Findings |
The primary safety objective was to demonstrate that the upper bound of the 95% confidence interval for the cumulative 5-year rate of adverse events related to the tined lead requiring surgery was less than 33%. In the InSite study, the 5-year cumulative event rate was 22.4% (95% CI: 16.6%-27.7%). With an upper 95% CI limit of 27.7%, the study primary safety endpoint was met.
|
Final Effect Findings |
The primary effectiveness analysis demonstrated that, at 5 years post-implant, 67% of subjects were OAB responders (meaning reduced symptoms of urinary urge incontinence). In addition, 64%, and 57% of subjects were urge incontinence (UI) responders and urgency-frequency (UF) responders, respectively, at 5 years. Sensitivity analyses demonstrated similar results, indicating that the main study findings regarding the treatment effect of InterStim is impacted substantially by missing data.
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Study Strengths & Weaknesses |
Strengths of this study include a multi-center, prospective design of adequate sample size for long-term (5-year) evaluation of the safety and effectiveness endpoints. The main weakness of the study is the limited generalizability of the long-term results. Given the attrition rate of 26.9% at 5 years, the main study findings may be an over-estimate of true device performance by potentially excluding patients who were poor responders to InterStim treatment.
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Recommendations for Labeling Changes |
Labeling changes are recommended based on the long-term (5-years) safety and effectiveness results of the PAS.
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