Neuropathic Pain Syndrome Patient Study (MK-0000-072)

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to determine the best way to conduct clinical trials in patients with neuropathic pain (nerve pain). This study will see if generic pregabalin has any effect on neuropathic pain.

Official Title
-----------------
A Double-Blind, Placebo-Controlled, Enriched-Enrollment, Randomized Withdrawal Study to Evaluate an Optimal Methodology for Conducting Proof of Concept Trials in Patients With Chronic Neuropathic Pain Syndromes Using Pregabalin as a Test Drug

Conditions
-----------------
Neuralgia, Postherpetic, Diabetic Neuropathy, Painful Small-Fiber Neuropathy, Idiopathic Distal Sensory Polyneuropathy

Intervention / Treatment
-----------------
* Drug: Comparator: pregabalin
* Drug: Comparator: Placebo (unspecified)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patient has moderate to severe nerve pain due to one of the following conditions: Postherpetic neuralgia, Painful diabetic neuropathy, Small fiber neuropathy or idiopathic distal sensory polyneuropathy Patient is able to complete questionnaires in either English or Spanish Patient is at least 18 years of age Exclusion Criteria: Patient is either pregnant or breastfeeding Patient has a history of angioedema (swelling beneath the skin surface) or peripheral edema (foot, leg, and/or ankle swelling) Patient has a history of congestive heart failure Patient has a seizure disorder Patient has a history of drug and/or alcohol abuse within the past 1 year Patient failed treatment due to lack of pain relief with more than three drugs for nerve pain Patient has had cancer (except basal cell carcinoma) within the past two years Patient anticipates the need for surgery while participating in the study Patient has a reported history of hepatitis B, C, or HIV infection Patient has another type of pain that is more painful than the nerve pain Patient has generalized anxiety disorder, untreated depression, psychosis, or post-traumatic stress disorder Patient is involved in litigation or receives worker's compensation related to nerve pain

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: A<br>Patients in Group A will remain on pregabalin (up to 600 mg/day po) treatment for the entire double-blind period. | Drug: Comparator: pregabalin<br>* pregabalin (up to 600 mg/day by mouth (po)). Duration of Treatment: 6 Weeks<br>|
| Placebo Comparator: B<br>Patients in Group B will be treated with placebo. | Drug: Comparator: Placebo (unspecified)<br>* pregabalin Pbo (up to 600 mg/day by mouth (po)). Duration of Treatment: 6 Weeks<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Daily Evening Patient Reported Pain Intensity Scores | Change from mean of last 3 days of maintenance period to last 3 days of double-blind period; Pain Intensity was rated on a 0-10 numeric rating scale (NRS: 0=no pain, 10=worst pain you can imagine) | Baseline and 6 Weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 'Time to Efficacy Failure' During the Randomized Withdrawal Portion of the Study | Time to treatment failure (3 day mean of average 24 hour pain intensity ≥ 4 with at least a 30% increase relative to the last 3 days prior to randomization) | 6 Weeks |