A Study of the Safety and Efficacy of AGN-214868 in Patients With Postherpetic Neuralgia

Study Overview
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Brief Summary
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This study will evaluate the safety and efficacy of AGN-214868 in patients with postherpetic neuralgia (PHN) - nerve pain.

Conditions
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Neuralgia, Postherpetic

Intervention / Treatment
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* Drug: AGN-214868
* Drug: Placebo to AGN-214868


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Persistent postherpetic neuralgia (PHN) with nerve pain present for at least 9 months after onset of herpes zoster skin rash Exclusion Criteria: Female patients with reproductive potential Active herpes zoster skin rash Current or anticipated treatment with acupuncture, TNS, or steroids Current or anticipated use of topical analgesic agents with PHN Treatment with botulinum toxin therapy of any serotype within the prior 12 weeks

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: AGN-214868 3.25 μg<br>AGN-214868 injected into areas of postherpetic neuralgia pain for a total dose of 3.25 μg per treatment. | Drug: AGN-214868<br>* AGN-214868 injected into areas of postherpetic neuralgia pain for total dose per treatment.<br>|
| Experimental: AGN-214868 16.25 μg<br>AGN-214868 injected into areas of postherpetic neuralgia pain for a total dose of 16.25 μg per treatment. | Drug: AGN-214868<br>* AGN-214868 injected into areas of postherpetic neuralgia pain for total dose per treatment.<br>|
| Placebo Comparator: Placebo<br>Placebo to AGN-214868 injected into areas of postherpetic neuralgia pain per treatment. | Drug: Placebo to AGN-214868<br>* Placebo to AGN-214868 injected into areas of postherpetic neuralgia pain per treatment.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in the Average Pain Intensity Score at Week 12 | Participants rated the severity of their daily pain in the previous 7 days using a 10 point scale where 0=no pain to 10=pain as bad as you can imagine. A negative change from Baseline indicated improvement. | Baseline, Week 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Area of Spontaneous Pain | A tracing of the area of spontaneous pain was made and sent to an independent central reading center for measurement. The area of spontaneous pain was measured in centimeters squared (cm^2) at Baseline and Week 12. A negative change from Baseline indicated improvement. | Baseline, Week 12 | 
| Change From Baseline in Area of Allodynia | A tracing of the area of allodynia (pain to touch) was made and sent to an independent central reading center for measurement. The area of allodynia was measured in centimeters squared (cm^2) at Baseline and Week 12. A negative change from Baseline indicated improvement. | Baseline, Week 12 | 
| Change From Baseline in Evoked Pain Score in the Area of Allodynia | Participants were asked to rate the unpleasantness (pain to touch) after 3 brush strokes in the area of allodynia on a 100 point scale where 0=no pain to 100=worst pain imaginable. A negative change from Baseline indicated improvement. | Baseline, Week 12 |