Efficacy, Tolerability, and Safety of NXN-462 in Patients With Post-Herpetic Neuralgia

Study Overview
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Brief Summary
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The purpose of this study is to investigate whether NXN-462, a selective nNOS inhibitor, is effective in reducing pain levels in patients with post-herpetic neuralgia.

Detailed Description
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NXN-462 is designed to target the nitric oxide synthase system (NOS), specifically the neuronal NOS (nNOS) isoform. By design, NXN-462 is a potent inhibitor of nNOS with good affinity, and has little or no affinity for a range of G protein-coupled receptors, ion channels, and enzymes. NXN-462 is being developed as an oral therapy for the treatment of neuropathic pain syndromes, including PHN. This drug design strategy provides a new therapeutic paradigm for the treatment of chronic neuropathic pain.

Official Title
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A Double-Blind, Randomized, Placebo-Controlled, Parallel Group Study to Evaluate the Efficacy, Tolerability, and Safety of NXN-462 in Patients With Post-Herpetic Neuralgia (PHN)

Conditions
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Post Herpetic Neuralgia

Intervention / Treatment
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* Drug: NXN-462
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male, or a non-pregnant, non-lactating female 18 years or older Have voluntarily provided written informed consent able to speak, read, write, and understand English clinical diagnosis of PHN for a minimum of 6 months pain intensity score of ≥3 on a 0-10 Numerical Rating Scale (NRS) at the Screening Visit generally in good health (other than PHN) at Screening Exclusion Criteria: Are pregnant and/or lactating Diagnosis of any chronic pain syndrome that would interfere with the assessment of PHN evidence of multiple causes of neuropathic pain,e.g.lumbar radiculopathy in the lumbosacral area Have had neuroablation or neurosurgical intervention for PHN Have been taking opioid analgesics for >5 days/week Have received nerve block or intrathecal analgesia within 6 weeks of the study History of significant gastrointestinal disease, liver disease, renal disease, endocrine disease, or cardiovascular disease clinically significant abnormal clinical laboratory test results or vital signs Are immunocompromised or immunosuppressed for any reason History of alcohol or other substance abuse (not including nicotine or tobacco) within 5 years Significant psychiatric disorder which requires drug treatment (except depression or anxiety treated with Selective Serotonin Re-uptake Inhibitors) Have received an investigational drug or have used an investigational device within 30 days of Screening. Have previously been randomized to this study

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: NXN-462<br>capsule, 200 mg, bi.d. 28-days | Drug: NXN-462<br>* Study drug is to be self-administered twice each day by the patient. Each day the first dose of study drug should be taken preferably one hour prior to, OR one hour after the first meal (breakfast) of the day. The second and final dose each day should be taken with a glass of water at least one hour after the last meal immediately before retiring to sleep.<br>* Other names: NXN-462 dihydrochloride;|
| Placebo Comparator: Placebo<br>capsule, b.i.d. 28-days | Drug: Placebo<br>* Study drug is to be self-administered twice each day by the patient. Each day the first dose of study drug should be taken preferably one hour prior to, OR one hour after the first meal (breakfast) of the day. The second and final dose each day should be taken with a glass of water at least one hour after the last meal immediately before retiring to sleep.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline to the last week of treatment in daily pain scores | Change from baseline to the last week of treatment in daily (24-hour recall) pain scores comparing NXN-462 with placebo | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| average weekly change in pain score from baseline to the end of the Treatment Period |  | four weeks | 
| Analysis of percent change from baseline in daily pain score |  | four weeks | 
| percentage of responders | subjects with a ≥30% and ≥50% reduction in pain score from baseline to the last week of treatment | four weeks | 
| Percentage of subjects with moderate or much improvement at the end of the Treatment Period, according to Patient Global Impression of Change |  | four weeks | 
| Change from baseline to the end of the Treatment Period in Pain Quality Assessment Scale score |  | four weeks | 
| Rescue medication consumption |  | four weeks | 
| Adverse events (AEs), vital signs, and clinical laboratory tests |  | six weeks | 
| Change from baseline to the end of the Treatment Period in Modified Brief Pain Inventory Short Form score, pain interference subscale |  | four weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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shingles,, neuropathic pain, post herpetic neuralgia, sleep