The SNAP Trial: SPRINT® Peripheral Nerve Stimulation for the Treatment of Neuropathic Post-Amputation Pain (SNAP)

• ClinicalTrials.gov Identifier: NCT03783689
• Recruitment Status: Terminated
• First Posted: December 21, 2018
• Results First Posted: November 29, 2023
• Last Update Posted: November 29, 2023
• Sponsor: SPR Therapeutics, Inc.
• Information provided by (Responsible Party): SPR Therapeutics, Inc.

Study Description

Brief Summary:

The purpose of this study is to determine if pain can be relieved by delivering small amounts of electricity (called "electrical stimulation") to the nerves in an individual's amputated leg.This study will involve the use of a Peripheral Nerve Stimulation (PNS) System that is made by SPR Therapeutics (the sponsor of the study). The PNS System was cleared by the FDA for up to 60 days of use for the management of chronic pain, including extremity (leg) pain.

Condition or disease	Intervention/treatment	Phase
Neuropathic Pain; Amputation	Device: SPRINT Peripheral Nerve Stimulation (PNS) System	Not Applicable

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 38 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Double (Participant, Outcomes Assessor)
• Primary Purpose: Treatment
• Official Title: The SNAP Trial: SPRINT® Peripheral Nerve Stimulation for the Treatment of Neuropathic Post-Amputation Pain in a Randomized, Double-blinded, Placebo-controlled, Multicenter Trial
• Actual Study Start Date: December 18, 2018
• Actual Primary Completion Date: September 22, 2022
• Actual Study Completion Date: September 22, 2022

Arms and Interventions

Arm	Intervention/treatment
Active Comparator: Group 1 (Treatment); Subjects in Group 1 will have Leads placed in the residual limb in the upper leg. These subjects will then use the SPRINT Peripheral Nerve Stimulation (PNS) System and will receive electrical stimulation for 8 weeks.	Device: SPRINT Peripheral Nerve Stimulation (PNS) System; The SPRINT System delivers mild electrical stimulation to nerves in the residual limb. The SPRINT System includes two small wires (called "Leads") that are placed through the skin in the upper leg. It also includes a device worn on the body that delivers stimulation (called the SPRINT Stimulator).; Other Names: SPRINT; SPRINT System
Sham Comparator: Group 2 (Control); Subjects in Group 2 will have Leads placed in the residual limb in the upper leg. These subjects will then use the SPRINT Peripheral Nerve Stimulation (PNS) System and receive 8 weeks of sham stimulation. Subjects will then have the option to crossover and receive stimulation therapy.	Device: SPRINT Peripheral Nerve Stimulation (PNS) System; The SPRINT System delivers mild electrical stimulation to nerves in the residual limb. The SPRINT System includes two small wires (called "Leads") that are placed through the skin in the upper leg. It also includes a device worn on the body that delivers stimulation (called the SPRINT Stimulator).; Other Names: SPRINT; SPRINT System

Outcome Measures

Primary Outcome Measures :

1. Number of Subjects With ≥50% Reduction in Average Post-Amputation Pain (Residual Limb Pain [RLP] and/or Phantom Limb Pain [PLP]) [ Time Frame: Baseline and 5 to 8 weeks post-start of treatment (SOT) ]
   All subjects were asked to complete daily diaries to record their average residual limb pain and/or phantom pain intensities during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average pain scores were calculated across the 7-day period for each region of pain at baseline and across weeks 5 to 8 post-start of treatment. Percent reduction was then calculated for each subject's qualifying region of pain (residual limb and/or phantom limb pain with qualifying average pain intensity at baseline). To be considered a success, subjects must have experienced ≥ 50% reduction in all qualifying regions of pain compared to their 7-day baseline diary average pain score(s). The number of successes is presented.
2. Number of Subjects That Experienced at Least One Study-Related Adverse Event [ Time Frame: Up to 14 months for each Group 1 subject and up to 18 months for each Group 2 subject (time from baseline to last study visit) ]
   At each study visit following the baseline assessment at Visit 1, subjects were questioned if any changes in their medical status or condition have occurred since their previous visit. If the subject experienced a change that was a study-related adverse event, an Adverse Event Form was completed by the site. The number of subjects that experienced at least one study-related adverse event is reported here.

Secondary Outcome Measures :

1. Pain Interference [ Time Frame: Visit 1 (Baseline), Visit 7 (4-weeks post-start of treatment [SOT]), Visit 11 (8-weeks post-SOT), Visit 13 (3-months post-SOT), Visit 14 (6-months post-SOT), and Visit 16 (12-months post-SOT) ]
   Question 9 of the Brief Pain Inventory-Short Form (BPI-9) is a 7-part question that assesses the level of interference that subjects experience in their daily lives due to pain. The 7 categories are general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life. Subjects were asked to rate how much their post-amputation residual and/or phantom limb pains interfere with each aspect on an 11-point numerical scale where 0 represents "Does Not Interfere" and 10 represents "Completely Interferes." The average of these 7 scores was calculated for each subject at each time point. Percent reduction was then calculated for each subject's qualifying region of pain (residual limb and/or phantom limb pain with qualifying average pain intensity at baseline). To be considered a success, subjects must have experienced ≥ 50% reduction in all qualifying regions of pain compared to baseline. The number of successes is presented.
2. Pain Disability Index (PDI) [ Time Frame: Visit 1 (Baseline), Visit 7 (4-weeks post-start of treatment [SOT]), Visit 11 (8-weeks post-SOT), Visit 13 (3-months post-SOT), Visit 14 (6-months post-SOT), and Visit 16 (12-months post-SOT) ]
   The Pain Disability Index (PDI) is a validated survey measuring the degree to which pain disrupts 7 categories of life activities on a scale from 0 to 10, with higher scores indicating greater disability. The 7 scores were summed for each subject to provide an overall pain disability score ranging from 0 to 70. A score of 0 indicates no disability while a score of 70 signifies that all of the activities in which the individual would normally be involved have been totally disrupted or prevented by pain. To be considered a success, subjects must have a ≥ 10-point reduction in their total PDI score at each time point compared to their baseline score. The number of subjects successful at each time point is reported.
3. Patient Global Impression of Change (PGIC) Survey [ Time Frame: Visit 7 (4-weeks post-Start of Therapy [SOT]), Visit 11 (8-weeks post-SOT), Visit 13 (3-months post-SOT), Visit 14 (6-months post-SOT), and Visit 16 (12-months post-SOT) ]
   The Patient Global Impression of Change (PGIC) Survey asks subjects to rate their improvement with treatment on a 7-point scale ranging from -3 to 0 to +3, where -3 represents "very much worse," 0 is "no change," and +3 represents "very much improved" as compared to before stimulation treatment. The subjects combine all the components of their experience into one overall score. The mean rank score of each group was calculated for each time frame.
4. Pain Catastrophizing Scale (PCS) [ Time Frame: Visit 1 (Baseline), Visit 7 (4-weeks post-Start of Treatment [SOT]), and Visit 11 (8-weeks post-SOT) ]
   The Pain Catastrophizing Scale (PCS) questionnaire has 13 questions that assess rumination, magnification, and helplessness. Subjects are asked to think back on painful experiences in the past and reflect on how often they had specific thoughts or feelings. Each of the 13 questions is scored on a 5-point scale where 0 represents "not at all," and 4 represents "all the time." The scores from each question were summed for each subject to provide a total PCS score, with a possible range from 0 to 52 with higher scores indicating a greater tendency to catastrophize pain (i.e. a higher score indicates a worse outcome). The mean score for each time point is presented.
5. Pain Medication Usage [ Time Frame: Baseline, 1 to 4 weeks post-start of treatment (SOT), 5 to 8 weeks post-SOT, 3 months post-SOT, 6 months post-SOT, and 12 months post-SOT ]
   Subjects completed 7-day diaries in which they tracked their daily use of analgesic medications. Opioid analgesic usage was converted into a morphine equivalent dosage (MED), which is measured in units of morphine milligram equivalents (MME), for subjects who were using opioid analgesics at baseline. The average MED was calculated for each subject at each time point.
6. Number of Subjects With ≥ 50% Reduction in Average Post-Amputation Pain (Residual Limb Pain [RLP] and/or Phantom Limb Pain [PLP]) 1 to 4 Weeks After Start of Treatment [ Time Frame: Baseline and 1 to 4 weeks post-start of treatment (SOT) ]
   All subjects were asked to complete daily diaries to record their average residual limb pain and/or phantom pain intensities during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average pain scores were calculated across the 7-day period for each region of pain at baseline and across weeks 1 to 4 post-start of treatment (i.e., the first half of the 8-week treatment period). Percent reduction was then calculated for each subject's qualifying region of pain (residual limb and/or phantom limb pain with qualifying average pain intensity at baseline). To be considered a success, subjects must have experienced ≥ 50% reduction in all qualifying regions of pain compared to their 7-day baseline diary average pain score(s). The number of successes is presented.
7. Number of Subjects With ≥ 50% Reduction in Average Residual Limb Pain (RLP) 5 to 8 Weeks After Start of Treatment [ Time Frame: Baseline and 5 to 8 weeks post-start of treatment (SOT) ]
   All subjects were asked to complete daily diaries to record their average residual limb pain and/or phantom pain intensities during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average residual limb pain scores were calculated across the 7-day period at baseline and for weeks 5 to 8 post-start of treatment (for subjects with qualifying residual limb average pain intensity at baseline). Percent reduction from baseline was then calculated, and the number of subjects that experienced ≥ 50% reduction in residual limb pain are reported.
8. Number of Subjects With ≥ 50% Reduction in Average Phantom Limb Pain (PLP) 5 to 8 Weeks After Start of Treatment [ Time Frame: Baseline and 5 to 8 weeks post-start of treatment (SOT) ]
   All subjects were asked to complete daily diaries to record their average residual limb pain and/or phantom pain intensities during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average phantom limb pain scores were calculated across the 7-day period at baseline and for weeks 5 to 8 post-start of treatment (for subjects with qualifying phantom limb average pain intensity at baseline). Percent reduction from baseline was then calculated, and the number of subjects that experienced ≥ 50% reduction in phantom limb pain are reported.
9. Durability of Treatment Effect on Average Post-Amputation Pain Intensity (Residual Limb Pain [RLP] and/or Phantom Limb Pain [PLP]) [ Time Frame: Baseline, 3-months post-Start of Treatment (SOT), 6-months post-SOT, and 12-months post-SOT ]
   All subjects were asked to complete daily diaries to record their average residual limb pain and/or phantom limb pain intensities during the past 24 hours on each day of a 7-day period using an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." The average pain scores were calculated across the 7-day period for each region of pain at baseline and at 3, 6, and 12 months post-start of treatment. Percent reduction was then calculated for each subject's qualifying region of pain (residual limb and/or phantom limb pain with qualifying average pain intensity at baseline) at each time point. To be considered a success, subjects must have experienced ≥ 50% reduction in all qualifying regions of pain compared to their 7-day baseline diary average pain score(s). The number of successes is presented.

Eligibility Criteria

• Ages Eligible for Study: 21 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Criteria

Key Inclusion Criteria:

• At least 21 years old
• Lower extremity amputation
• Experiencing residual limb (stump) and/or phantom limb pain
• Healed amputation and healthy residual limb based upon the investigator's evaluation

Key Exclusion Criteria:

• Conditions with increased risk of infection (e.g., compromised immune system or history of recurrent skin infections)
• Implanted electronic device
• Pregnancy

Contacts and Locations

Locations

United States, Arizona

Pain Center of Arizona - Hope Research Institute

Phoenix, Arizona, United States, 85018

United States, California

University of California San Diego

La Jolla, California, United States, 92093

United States, Florida

Lake Nona Medical Arts

Orlando, Florida, United States, 32827

James A. Haley Veterans' Hospital

Tampa, Florida, United States, 33612

United States, Georgia

Better Health Clinical Research

Newnan, Georgia, United States, 30265

United States, Illinois

Northwestern University

Chicago, Illinois, United States, 60611

United States, Kansas

Neuroscience Research Center, LLC

Overland Park, Kansas, United States, 66210

United States, Kentucky

OtriMed Clinical Research Center

Edgewood, Kentucky, United States, 41017

United States, Massachusetts

MedVadis Research

Waltham, Massachusetts, United States, 02451

United States, New Jersey

Premier Pain Centers

Shrewsbury, New Jersey, United States, 07702

Pain Management Center

Voorhees, New Jersey, United States, 08043

United States, North Carolina

Duke University

Durham, North Carolina, United States, 27710

Center for Clinical Research

Winston-Salem, North Carolina, United States, 27103

United States, Texas

The University of Texas Health Science Center at San Antonio

San Antonio, Texas, United States, 78229

Sponsors and Collaborators

SPR Therapeutics, Inc.

  Study Documents (Full-Text)

Documents provided by SPR Therapeutics, Inc.:

Study Protocol  [PDF] January 15, 2021

Statistical Analysis Plan  [PDF] September 20, 2023

More Information

• Responsible Party: SPR Therapeutics, Inc.
• ClinicalTrials.gov Identifier: NCT03783689
• Other Study ID Numbers: 0147-CSP-000
• First Posted: December 21, 2018
• Results First Posted: November 29, 2023
• Last Update Posted: November 29, 2023
• Last Verified: November 2023

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: Yes
• Product Manufactured in and Exported from the U.S.: No

Additional relevant MeSH terms:

Neuralgia; Peripheral Nervous System Diseases; Neuromuscular Diseases; Nervous System Diseases; Pain; Neurologic Manifestations