WallFlex Pancreatic Metal Stent for Pancreatic Duct Strictures

Study Overview
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Brief Summary
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To prospectively document the performance of a FCSEMS for treatment of pancreatic duct strictures in patients with painful chronic pancreatitis.

Detailed Description
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This study is a prospective, single arm, pre-approval study. Treatment of up to 92 patients will take place at up to 15 clinical centers. Patient who meet all eligibility criteria will receive the WallFlex Pancreatic stent for up to 6 months stent indwell and 6 months follow-up after stent removal.

Official Title
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Fully Covered Self Expanding Metal Stents (FCSEMS) for Pancreatic Duct Strictures in Patients With Chronic Pancreatitis

Conditions
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Chronic Pancreatitis

Intervention / Treatment
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* Device: Pancreatic fully-covered self-expanding metal stent (FCSEMS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 or older Willing and able to comply with study procedures and follow-up schedule and provide written informed consent to participate in study Chronic pancreatitis induced stricture of Cremer Type IV, namely distal dominant stricture with upstream ductal dilation. For patients with one prior plastic pancreatic stent: VAS Pain Score and Frequency of Pain sectors of the Izbicki pain scale at the time of placement of the plastic stent. Availability of narcotic dosage for at least one month prior to baseline visit for patients who do not have a prior plastic stent or availability for one month prior to placement of prior plastic stent, where applicable. VAS Pain Score of ≥ 20 before study stent placement for patients without a prior plastic pancreatic stent. VAS Pain Score of ≥ 20 before initial plastic pancreatic stent placement for patients with a prior plastic pancreatic stent indwelling for 90 days or less before study stent placement. VAS Pain Score is captured via Izbicki pain scale. Pain occurring weekly or more frequently (assessed by Frequency of Pain sector of the Izbicki pain scale) as reported before study stent placement for patients without a prior plastic pancreatic stent, or before placement of initial plastic pancreatic stent for patients with a prior plastic pancreatic stent indwelling for 90 days or less before study stent placement. Minimum 5 mm diameter of dilated duct immediately upstream of pancreatic duct stricture Prior clearance of pancreatic stones where needed If pancreatic duct stone clearance prior to placement of the study stent includes ESWL, then a plastic pancreatic stent may be placed immediately after the ESWL procedure at the discretion of the Investigator, for example, if there is concern about stone fragments of stone sludge in side branches of the pancreatic duct, and may be left indwelling for 30-90 days. If new pancreatic duct stones requiring ESWL have formed by the time of intended study stent placement, then the patient will not receive the study stent and be excluded from the study. Further treatment of the patient will be provided per standard of practice outside of the study. In case the study stent is not placed during the same session in which the plastic stent is removed, the pain score needs to be collected again prior to study stent placement. Prior endoscopic pancreatic sphincterotomy (EPS), historically or to be provided at time of SEMS placement as applicable. Exclusion Criteria: Pancreatic or peri-ampullary cancer with or without pancreatic duct strictures caused by malignancy Biliary strictures caused by chronic pancreatitis that are symptomatic and/or in need of therapeutic intervention Perforated duct Ansa pancreatica Presence of pancreatic cysts suspected to be cystic tumor or requiring transmural drainage Duodenal/groove pancreatitis Autoimmune pancreatitis Pancreatic duct stenoses not located in the head of the pancreas Failed access during an attempted ERCP on a prior date at the investigational center Duration of indwell of one single plastic pancreatic stent or cumulative duration of consecutive single plastic pancreatic stents immediately prior to study stent placement exceeding 90 days History of prior single pancreatic plastic stent(s) followed by a stent-free period shorter than 1 year before enrollment into the study History of prior side-by-side multiple pancreatic plastic stents up to one year prior to enrollment History of prior pancreatic metal stent(s) Reported recent history of acute relapsing pancreatitis in the absence of chronic pancreatitis Patients for whom endoscopic techniques are contraindicated Patients who are currently enrolled in another investigational study that would directly interfere with the current study, without prior written approval from the sponsor Inability or refusal to comply with the follow-up schedule including patients living at such a distance from the investigational center that attending follow-up visits would be unusually difficult or burdensome

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: WallFlex FCSEMS Recipients<br>The WallFlex™ Pancreatic RX Fully Covered Soft Stent System consists of a flexible delivery system preloaded with a self-expanding pancreatic metal stent. Patients who meet all eligibility criteria will receive the WallFlex Pancreatic stent for up to 6 months stent indwell and 6 months follow-up after stent removal. A patient is considered enrolled after signing the study-specific Informed Consent Form (ICF). Patients who sign the ICF but subsequently do not meet one or more of the selection criteria will be considered screen failures and excluded from the study. | Device: Pancreatic fully-covered self-expanding metal stent (FCSEMS)<br>* The WallFlex™ Pancreatic RX Fully Covered Soft Stent System consists of a flexible delivery system preloaded with a self-expanding pancreatic metal stent.<br>* Other names: WallFlex;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Reduction | The self-reported pain score (0-100) was the mean of the Visual Analogue Scale (VAS) and Izbicki Frequency of Pain subscore (sum treated as a continuous variable).The primary efficacy endpoint was the proportion of patients who had complete (pain score ≤ 10) or partial (pain score ˃ 10 but reduced at least 50% compared to pain as baseline) pain relief by 6 months after FCSEMS removal or observation of CDM or partial stent migration. Primary efficacy endpoint failure included any of the following: 1) no pain relief, 2) complete or partial pain relief in the setting of a 50% higher average daily narcotic dose compared to the patient's daily average narcotic dose in the month prior to baseline and at 6 months post-stent removal/observation of CDM, 3) stent migration in setting of recurring pain (VAS Pain Score of ≥ 20), 4) restenting in the setting of recurring pain. | Baseline to 6 months post-stent removal or 6 months post-observation of complete or partial stent migration | 
| Rate of Related SAEs From WallFlex Pancreatic Stent Placement to End of Study | The primary safety endpoint was the rate of serious adverse events (SAEs) related to the FCSEMS or study procedures from FCSEMS placement to end of study follow-up. Pain thought to be caused by FCSEMS pancreatic stent expansion was reported but did not count towards the endpoint if all three of the following conditions applied: Pain managed by medication, with the exception of injectable narcotic use for more than 24 hours. Pain not causing pancreatic FCSEMS removal. Pain resolved by 72 hours after pancreatic FCSEMS placement. | Baseline to 6 months post-stent removal or 6 months post-observation of complete or partial stent migration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stent Placement Success | Satisfactory position is defined as the stent being across the stricture, without visible occluding impaction at the genu of the pancreatic duct and with distal end of the stent visible in the duodenum. | Assessed upon study stent placement. This endpoint is assessed at the Study Stent Placement visit (Day 0). | 
| Endoscopic Stent Removal Success | Endoscopic stent removal success is defined as ability to remove stent endoscopically (forceps, snare) without serious stent removal-related adverse events. | Assessed at study stent removal or observation of complete or partial stent migration. This is endpoint is assessed through the Month 6 Study Stent Removal visit. | 
| Stent Migration Rate | Stent migration is the change in location of a stent from its originally placed location. In this study, pancreatic stent migration was noted as partial or complete and either proximal (i.e., into the pancreas) or distal (i.e., out of the pancreas). | Study stent placement through 6 months post-stent removal or 6 months post-observation of complete or partial stent migration | 
| Restenting Rate | Restenting is the placement of a non-study stent due to no improvement in clinical status and associated persistence of stricture following removal or complete distal migration of the study stent. | Study stent removal or observation of study stent migration through 6 months post-stent removal or 6 months post-observation of complete or partial stent migration | 
| Secondary Stricture Rate | A secondary stricture is a ductal narrowing located at the intraductal edge of the study stent. | Study stent placement through 6 months post-stent removal or 6 months post-observation of complete or partial stent migration |