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| General |
| Study Status |
Ongoing |
Application Number /
Requirement Number |
P220025 / PAS002 |
| Date Original Protocol Accepted |
10/12/2023
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| Date Current Protocol Accepted |
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| Study Name |
PROMISE III Post-Approval Study
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| Device Name |
LimFlow System
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| Clinical Trial Number(s) |
NCT03970538
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| General Study Protocol Parameters |
| Study Design |
Prospective Cohort Study
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| Data Source |
New Data Collection
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| Comparison Group |
No Control
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| Analysis Type |
Descriptive
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| Study Population |
Transit. Adolescent B (as adults) : 18-21 yrs,
Adult: >21
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| Detailed Study Protocol Parameters |
| Study Objectives |
This is a prospective, single-arm, multi-center study.
To provide additional information on the LimFlow System for creating an AV connection in the below the knee (BTK) vascular system using an endovascular, minimally invasive approach to arterialize the pedal veins for the treatment of chronic limb-threatening ischemia in subjects ineligible for conventional endovascular or surgical limb salvage procedures.
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| Study Population |
Subjects who are confirmed as “no option” (ineligible for conventional endovascular or surgical limb salvage procedures) by the treating physician. “No option” is defined as either a) absence of a usable pedal artery target (endovascular or surgical approach), or b) the presence of a pedal artery target with absence of a viable single-segment vein in either lower extremity or either arm that could be used for autogenous vein conduit.
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| Sample Size |
The study will enroll up to 100 subjects.
Assumptions for sample size estimation: A sample size of 100 subjects with an estimated proportion of 54% success would provide a sufficiently precise estimate with a two-sided 95% confidence interval half-width of 0.0977 or +/- 10%.
Up to 25 sites will be enrolled in the United Sates. Individual site enrollment is capped at 20% of total enrollment. It is estimated that the overall general loss to follow-up will be 10% at the time of primary analysis, and a true loss to follow up rate <10% will incur censoring while a loss > 10% will require sensitivity analyses.
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| Key Study Endpoints |
Primary Endpoints Amputation Free Survival (AFS) defined as freedom from major amputation (defined as above-ankle amputation of the index limb) and death (all-cause mortality) at 6 months. Secondary Endpoints: Secondary endpoints to be evaluated at 30days, then 6 months through 36 months • Primary patency • Primary Assisted Patency • Secondary Patency • Limb Salvage • Change in Rutherford Classification • Technical Success • Procedure Success • Target wound Healing • All Wound Area Reduction • Freedom from Contrast Induced Nephropathy • Procedure Time • Radiation Exposure • Contrast Volume
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| Follow-up Visits and Length of Follow-up |
Hospital discharge, 14 days, 30 days, 3 and 6 months, at 1 year 2 years and 3 years. Subjects will be followed for 3 years
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| Interim or Final Data Summary |
| Interim Results |
Safety Results:
All-cause mortality at 6 months was 8.9% (7/79). Target limb major amputation at 6 months was 14.8% (13/88). Amputation free survival at 6 months was 80.7% for the modified ITT population and 83.2% for per protocol population.
Effectiveness Results:
Technical Success rate was 100/103 (97.1%) Procedure Success rate was 81/103 (78.6%). At 6 months 78.3% (54/69) of primary wound status were reported as healed or healing and 10.1% (7/69) as stable; Another 10.1% (7/69) of primary wounds were reported as worsening.
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| Actual Number of Patients Enrolled |
One hundred (100) subjects were enrolled in the PROMISE III PAS as of August 29, 2025. Twelve (12) additional subjects were enrolled in the PROMISE III sub-study. A total of 103 Limbs were treated.
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| Actual Number of Sites Enrolled |
24
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| Patient Follow-up Rate |
Follow-up visit completed at 1, 3 and 6 months was 97.9% (92/94), 95.5% (85/89) and 100% (80/80) respectively.
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