Study of Capsaicin Patch for the Management of Peripheral Neuropathic Pain

Study Overview
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Brief Summary
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The efficacy and safety of the low concentration [0.65% (50 µg/cm2) and 1.25% (100 µg/cm2)] capsaicin patches and compared them to conventional 0.075% capsaicin cream and placebo patch in patients suffering from peripheral neuropathy

Official Title
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Efficacy and Safety of 0.625% and 1.25% Capsaicin Patch in the Management of Peripheral Neuropathic Pain ; Early Phase II, Multi-center, Randomized, and Semi-double Blind Controlled Clinical Trial

Conditions
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Peripheral Nerve Injury, Postherpetic Neuralgia

Intervention / Treatment
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* Drug: CAPNP, 50 ug/cm2 capsaicin patch
* Drug: CAPNP, 100 ug/cm2 capsaicin patch
* Drug: 0.075% capsaicin cream
* Other: Placebo patch


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients who are 18 years of age or older aged having chronic peripheral neuropathy related with a diagnosis of either PHN or DPN patients with chronic peripheral neuropathic pain for more than 3 months with an 11-pointed Numeric Rating Scale (NRS) pain score ≥ 4 patients with a diagnosis of PHN were eligible if at least 3 months had elapsed since shingles vesicle crusting patients with DPN and well controlled diabetes were asked to maintain a stable dose of oral hypoglycemic or insulin during the study period patients taking concomitant pain medications such as anticonvulsants, antidepressants, anxiolytics, and opioids including tramadol were required to maintain a stable dose for at least 4 weeks before the study enrollment any conservative therapies such as TENS, physical therapy, chiropractic, massage, biofeedback, or yoga were stopped at least 5 weeks before the enrollment women of childbearing age were required to have a negative pregnancy test and were to be willing to use an effective method of contraception for at least 28 days after the last exposure to study medication Exclusion Criteria: diffusely distributed neuropathic pain resulting from spinal stenosis, postoperative origin, complex regional pain syndrome, or genetic neurological disease, or significant pain outside the target area significant pain of an etiology other than PHN or DNP other severe acute or chronic medical or psychiatric condition, or laboratory abnormality that may increase the risk associated with study participation or with investigational product administration or may interfere with compliance or the interpretation of study results andin the judgment of the investigator would make the subject inappropriate to participate in the study painful PHN areas located on the face or above the scalp hairline an implanted medical device for the treatment of neuropathic pain use of topically applied agents including capsaicin-containing products, a 5% lidocaine patch or similar products, local anesthetics, or steroids within the past 21 days hypersensitivity known to capsaicin; current use of any class 1 anti-arrhythmic drug; and uncontrolled diabetes mellitus or uncontrolled hypertension If patients have taken oral NSAID or COX2 Inhibitor, it should be stopped at least2 weeks before randomization; however acetaminophen for pain control was allowed up to 4g per day

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
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CAPNP, 50 ug/cm2 capsaicin patch<br>50 ug/cm2 capsaicin patch, 49cm2, 1patch/4days | Drug: CAPNP, 50 ug/cm2 capsaicin patch<br> <br> |
| Experimental: CAPNP, 100 ug/cm2 capsaicin patch<br>100ug/cm2 capsaicin patch, 49cm2, 1patch/4days | Drug: CAPNP, 100 ug/cm2 capsaicin patch<br> <br> |
| Active Comparator: 0.075% capsaicin cream<br>capsaicin cream qc/day | Drug: 0.075% capsaicin cream<br> <br> |
| Placebo Comparator: Placebo patch<br> | Other: Placebo patch<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean difference in the change of daily NRS pain score | Mean numeric change in numerical rating scale pain score from the baseline (Visit 2) to the score at weeks 6 (Visit 5) in each group | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of patients with >=30% or >=50% reduction in pain | The percentage of responders (>=30% reduction) and the percentage of patients achieving a >=50% in NRS pain scores were compared among groups | 6 weeks | 
| Daily Sleep Interference Scale |  | 2, 4, 6 weeks | 
| Clinical Global Impression for Improvement | Clinical Global Impression of Change by the physician and Patient Global Impression of Change by the patients were used to evaluate the subjective perception of decrease in pain intensity | 2, 4, 6 weeks | 
| EQ-5D | For EQ-5DTM Health Survey, mean change from the baseline (Visit 2) to the score at weeks 6 (Visit 5) was shown as frequencies and their percentages | 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peripheral Nerve Injury, Postherpetic Neuralgia