Trial Outcomes & Findings for Electrical Stimulation for the Treatment of Back Pain Using Peripheral Nerve Stimulation (PNS) (NCT NCT03179202)

Last Updated: 2022-08-05

Results Overview

All subjects were asked to complete daily diaries to record their average pain intensity on each day of a 7-day period. The pain intensity question was excerpted from the Brief Pain Inventory-Short Form Question 5 (BPI-5). The BPI-5 uses an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." For each subject, the mean score for the baseline and end of treatment (EOT) diary periods were calculated and percent reduction was determined. Subjects that achieved ≥30% reduction in pain, were considered successful.

Recruitment status

COMPLETED

Study phase

Target enrollment

166 participants

Primary outcome timeframe

Baseline and End of Treatment (EOT= 8-weeks post-start of treatment)

Results posted on

2022-08-05

Participant Flow

Recruitment began in June 2017 and was concluded in December 2019. Subjects were screened from the available pool of candidates who presented with chronic low back pain.

After obtaining informed consent, subjects were evaluated for eligibility.

Participant milestones

Participant milestones
Measure	Consented Subjects Subjects who signed an informed consent form.
Overall Study STARTED	166
Overall Study Enrolled/Received Leads	99
Overall Study Protocol Population	91
Overall Study COMPLETED	75
Overall Study NOT COMPLETED	91

Reasons for withdrawal

Reasons for withdrawal
Measure	Consented Subjects Subjects who signed an informed consent form.
Overall Study Screen Failure	67
Overall Study Subject Lost to Follow Up	12
Overall Study Withdrawal by Subject	7
Overall Study Adverse Event	3
Overall Study Unrelated Death Reported in All-Cause Mortality	1
Overall Study Other Reason: Incarceration after Enrollment	1

Baseline Characteristics

Electrical Stimulation for the Treatment of Back Pain Using Peripheral Nerve Stimulation (PNS)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Enrolled/Received Leads n=99 Participants Subjects who were consented, met eligibility criteria, and underwent Lead placement. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	64 Participants n=5 Participants
Age, Categorical >=65 years	35 Participants n=5 Participants
Age, Continuous	57.4 years STANDARD_DEVIATION 13.8 • n=5 Participants
Sex: Female, Male Female	50 Participants n=5 Participants
Sex: Female, Male Male	49 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	97 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	1 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	1 Participants n=5 Participants
Race (NIH/OMB) Black or African American	12 Participants n=5 Participants
Race (NIH/OMB) White	84 Participants n=5 Participants
Race (NIH/OMB) More than one race	1 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Region of Enrollment United States	99 participants n=5 Participants
Duration of Low Back Pain	17.2 years STANDARD_DEVIATION 14.7 • n=5 Participants
Employment Status Currently Working	44 Participants n=5 Participants
Employment Status On Leave of Absence	1 Participants n=5 Participants
Employment Status Retired (not due to health)	30 Participants n=5 Participants
Employment Status Homemaker	4 Participants n=5 Participants
Employment Status Unemployed	7 Participants n=5 Participants
Employment Status Student	2 Participants n=5 Participants
Employment Status Disabled and/or Retired Because of Low Back Pain	8 Participants n=5 Participants
Employment Status Other	3 Participants n=5 Participants

PRIMARY outcome

Timeframe: Baseline and End of Treatment (EOT= 8-weeks post-start of treatment)

Population: Protocol Population presented. EOT data were not available for eight subjects.

Outcome measures

Outcome measures
Measure	Protocol Population n=83 Participants Subjects who were consented, met eligibility criteria, underwent Lead Placement, and continued to meet eligibility criteria. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Number of Subjects That Experienced ≥30% Reduction in Average Low Back Pain Intensity	58 Participants

PRIMARY outcome

Timeframe: Up to 15 months for each subject from baseline to the last study visit

Population: All enrolled subjects that received leads are presented.

At each study visit following the baseline assessment at Visit 1, subjects were questioned if any changes in their medical status or condition has occurred since their previous visit. If the subject experienced a change that was an 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.

Outcome measures

Outcome measures
Measure	Protocol Population n=99 Participants Subjects who were consented, met eligibility criteria, underwent Lead Placement, and continued to meet eligibility criteria. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Number of Subjects That Experienced at Least One Study-Related Adverse Event	49 Participants

SECONDARY outcome

Timeframe: Baseline and End of Treatment (EOT= 8-weeks post-start of treatment)

Population: Protocol Population presented. EOT data were not available for eight subjects.

All subjects were asked to complete daily diaries to record their worst pain intensity on each day of a 7-day period. The pain intensity question was excerpted from the Brief Pain Inventory-Short Form Question 3 (BPI-3). The BPI-3 uses an 11-point numerical rating scale where 0 represents "No Pain" and 10 represents "Pain as bad as you can imagine." For each subject, the mean score for the baseline and end of treatment (EOT) diary periods were calculated. The mean score across all subjects for each time point is reported.

Outcome measures

Outcome measures
Measure	Protocol Population n=91 Participants Subjects who were consented, met eligibility criteria, underwent Lead Placement, and continued to meet eligibility criteria. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Worst Pain Intensity Baseline	7.7 score on a scale Standard Deviation 1.2
Worst Pain Intensity EOT	4.5 score on a scale Standard Deviation 2.1

SECONDARY outcome

Timeframe: Baseline and End of Treatment (EOT= 8-weeks post-start of treatment)

Population: Protocol Population presented. Data were not available for one subject at baseline and for eight subjects at EOT.

The Oswestry Disability Index (ODI) is a widely used assessment designed to measure the degree of disability in people with low back pain. This validated questionnaire includes topics concerning the intensity of pain, the subject's ability to perform normal daily activities such as personal care, walking, sitting, or standing, and how pain affects the subject's sex life, social life, and travel. The scale ranges from 0-100 and higher scores indicate greater disability due to low back pain. The mean score across all subjects at baseline and end of treatment (EOT) is reported here.

Outcome measures

Outcome measures
Measure	Protocol Population n=91 Participants Subjects who were consented, met eligibility criteria, underwent Lead Placement, and continued to meet eligibility criteria. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Oswestry Disability Index (ODI) Baseline	39.1 score on a scale Standard Deviation 12.1
Oswestry Disability Index (ODI) EOT	23.6 score on a scale Standard Deviation 12.6

SECONDARY outcome

Timeframe: Baseline and End of Treatment (EOT= 8-weeks post-start of treatment)

Population: Protocol Population presented. Data were not available for three subjects at baseline and five subjects at end of treatment (EOT).

The RAND 36-Item Short Form Health Survey is a widely accepted form used to quantify quality of life. The survey consists of 8 categories with a total of 36 questions regarding the subject's general health and activities. The survey assesses physical and emotional problems associated with pain during the past 4 weeks. Each category is scored on a 0-100 scale, where a higher score indicates a more favorable health state. The score for each category was calculated at baseline and End of Treatment (EOT) for each subject. The change in each category score from Baseline to EOT was then calculated for each subject (with a positive change indicating an increase in health-related quality of life). The mean and standard deviation of the subjects' changes in each category are presented below.

Outcome measures

Outcome measures
Measure	Protocol Population n=88 Participants Subjects who were consented, met eligibility criteria, underwent Lead Placement, and continued to meet eligibility criteria. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Mean Change in Health-Related Quality of Life Role Limitations due to Physical Health	26.6 score on a scale Standard Deviation 39.9
Mean Change in Health-Related Quality of Life Pain	21.6 score on a scale Standard Deviation 20.8
Mean Change in Health-Related Quality of Life Physical Functioning	13.2 score on a scale Standard Deviation 19.6
Mean Change in Health-Related Quality of Life Role Limitations due to Emotional Problems	12.2 score on a scale Standard Deviation 42.5
Mean Change in Health-Related Quality of Life Energy/Fatigue	12.8 score on a scale Standard Deviation 17.0
Mean Change in Health-Related Quality of Life Emotional well-being	7.2 score on a scale Standard Deviation 15.2
Mean Change in Health-Related Quality of Life Social Functioning	18.0 score on a scale Standard Deviation 22.5
Mean Change in Health-Related Quality of Life General Health	5.0 score on a scale Standard Deviation 15.1

SECONDARY outcome

Timeframe: Baseline and End of Treatment (EOT= 8-weeks post-start of treatment)

Population: Protocol Population presented. EOT data were not available for nine subjects.

The Beck Depression Inventory (BDI-II) is a validated, 21-question survey used to measure depression severity. Questions are rated on a scale from 0 to 3, and the scores from each question are totaled to provide an overall score ranging between 0 to 63. Scores from 0-13 indicate minimal depression, 14-19 mild depression, 20-28 moderate depression, and 29-63 indicates severe depression. The average total scores across subjects were calculated at baseline and end of treatment (EOT).

Outcome measures

Outcome measures
Measure	Protocol Population n=91 Participants Subjects who were consented, met eligibility criteria, underwent Lead Placement, and continued to meet eligibility criteria. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Beck Depression Inventory (BDI-II) Baseline	8.9 score on a scale Standard Deviation 5.6
Beck Depression Inventory (BDI-II) EOT	5.2 score on a scale Standard Deviation 5.1

SECONDARY outcome

Timeframe: 8-weeks post-Start of Treatment (SOT)

Population: Protocol Population presented. EOT data were not available for eight subjects.

The Patient Global Impression of Change (PGIC) asks subjects to rate their improvement with treatment on a 7-point scale where 1 represents "very much worse" and 7 represents "very much improved" as compared to before stimulation treatment. The subjects combine all the components of their experience into one overall score. The number of participants with each rating after 8 weeks of treatment is reported here.

Outcome measures

Outcome measures
Measure	Protocol Population n=83 Participants Subjects who were consented, met eligibility criteria, underwent Lead Placement, and continued to meet eligibility criteria. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Patient Global Impression of Change (PGIC) Survey Very Much Improved	12 Participants
Patient Global Impression of Change (PGIC) Survey Much Improved	39 Participants
Patient Global Impression of Change (PGIC) Survey Minimally Improved	23 Participants
Patient Global Impression of Change (PGIC) Survey No Change	8 Participants
Patient Global Impression of Change (PGIC) Survey Minimally Worse	0 Participants
Patient Global Impression of Change (PGIC) Survey Much Worse	1 Participants
Patient Global Impression of Change (PGIC) Survey Very Much Worse	0 Participants

SECONDARY outcome

Timeframe: Baseline and End of Treatment (EOT= 8-weeks post-start of treatment)

Population: Protocol Population presented. Data were not available for nine subjects at end of treatment (EOT).

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 low back pain interferes 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. The mean was taken across subjects for each time point.

Outcome measures

Outcome measures
Measure	Protocol Population n=91 Participants Subjects who were consented, met eligibility criteria, underwent Lead Placement, and continued to meet eligibility criteria. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Pain Interference Baseline	5.7 score on a scale Standard Deviation 2.0
Pain Interference EOT	2.8 score on a scale Standard Deviation 2.0

Adverse Events

Enrolled/Received Leads

Serious events: 4 serious events

Other events: 49 other events

Deaths: 1 deaths

Serious adverse events

Serious adverse events
Measure	Enrolled/Received Leads n=99 participants at risk Subjects who were consented, met eligibility criteria, and underwent Lead Placement. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Surgical and medical procedures Shoulder procedure	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Cardiac disorders Heart attack	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Breast Cancer	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Surgical and medical procedures Heart procedures	1.0% 1/99 • Number of events 2 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Melanoma	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Liver/Lymph node metastases	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Surgical and medical procedures SCS trial and permanent implant	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.

Other adverse events

Other adverse events
Measure	Enrolled/Received Leads n=99 participants at risk Subjects who were consented, met eligibility criteria, and underwent Lead Placement. Also includes subjects participating in sub-studies with modified eligibility criteria allowing a history of prior radiofrequency ablation or prior lumbar surgery.
Skin and subcutaneous tissue disorders Irritation at pad and/or Lead exit sites	16.2% 16/99 • Number of events 17 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Irritation or bruising at bandage site or connector cradles	19.2% 19/99 • Number of events 19 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Mild swelling following Lead removal	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Generalized itching	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Itching at pad and/or Lead exit sites	11.1% 11/99 • Number of events 11 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Itching at bandage site	13.1% 13/99 • Number of events 13 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Discoloration/bruising at Lead exit site	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Skin infection	2.0% 2/99 • Number of events 2 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Urticaria	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Discharge or bleeding from electrode/insertion site	3.0% 3/99 • Number of events 3 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Granuloma	2.0% 2/99 • Number of events 2 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Skin and subcutaneous tissue disorders Miscellaneous	2.0% 2/99 • Number of events 2 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders New leg pain	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Pain from Lead Placement	3.0% 3/99 • Number of events 3 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Pain/discomfort at lead site	5.1% 5/99 • Number of events 5 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Pain from stimulation	2.0% 2/99 • Number of events 3 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Uncomfortable stimulation	8.1% 8/99 • Number of events 8 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Worsening low back pain	4.0% 4/99 • Number of events 4 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Exacerbation of low back pain from medial branch block	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Shoulder and/or hip conditions	3.0% 3/99 • Number of events 4 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Thoracic pain/hematoma from fall	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Musculoskeletal and connective tissue disorders Pain (distal or unrelated to device location)	6.1% 6/99 • Number of events 6 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Cardiac disorders Shortness of breath	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Cardiac disorders Vasovagal dizziness following lead placement	2.0% 2/99 • Number of events 2 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Renal and urinary disorders Urinary tract infection	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
General disorders Bacterial pneumonia	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
General disorders Strep throat	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
General disorders Sinus infection	2.0% 2/99 • Number of events 2 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Surgical and medical procedures Sinuplasty	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Surgical and medical procedures Toenail removal	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Surgical and medical procedures Shoulder procedure	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.
Surgical and medical procedures Hip procedure	1.0% 1/99 • Number of events 1 • Each participant enrolled was assessed for adverse events from the time of informed consent through the 12-month follow up visit. The total assessment period was approximately 14 months for each participant.

Additional Information

Clinical Affairs

SPR Therapeutics

Phone: 216-378-9106

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place