Double-blind, controlled dose finding study NGX-4010 for the treatment of postherpetic neuralgia

Journal of Drugs in Dermatology, August, 2003

Sponsored by: NeurogesX

Purpose: The purpose of the study is to assess the efficacy, safety and tolerability of the high-concentration capsaicin path at three different dose levels (i.e., application durations) for the treatment of postherpetic neuralgia (PHN). Based on these data, an optimal dose for treatment of PHN will be selected. The study will also provide information about the efficacy, safety, and tolerability of repeated treatment(s) with the high-concentration capsaicin patch over one year.

Condition            Treatment or Intervention   Phase

Herpes Zoster        Drug: Capsaicin Patch       Phase II
Neuralgia
Pain
Peripheral Nervous
  System Diseases

Study Type: Interventional

Study Design: Treatment, Randomized, Double-Blind, Dose Comparison, Safety/Efficacy Study

Ages eligible for study: 18 years and above, both genders

Inclusion Criteria:

* Be in good health.

* Diagnosis of PHN made by the primary treating physician or Investigator, and at least 6 months post-vesicle crusting.

* Screening Pain Sum Score of 12 to 36.

* Intact, unbroken skin over the painful area(s) to be treated.

* If taking chronic pain medications, be on a stable (not PRN) regimen for at least 21 days prior to Treatment Visit (Day 0) and willing to maintain medications at same stable dose(s) and schedule throughout the study.

* Female subjects with child-bearing potential must have a negative serum beta hCG pregnancy test, to be performed at the Screening Visit.

* All subjects must be willing to use effective methods of birth control and/or refrain from participating in a conception process during the study and for 30 days following experimental drug exposure.

* Be willing and able to comply with protocol requirements for the duration of study participation. (Such requirements include, but are not limited to: completing a daily pain diary, attending all study visits, and refraining from elective surgery and extensive travel during study participation.)

Exclusion Criteria:

* Significant pain of an etiology other than PHN, for example, compression-related neuropathies, e.g., spinal stenosis, or fibromyalgia or arthritis. Subjects must not have significant ongoing pain from other cause(s) that may interfere with judging PHN-related pain.

* Painful PHN areas located only on the face, above the hairline of the scalp, and/or in proximity to mucous membranes. (Investigational treatment with NGX-4010 is not allowed in these areas.)

* Any implanted medical device (spinal cord stimulator, intrathecal pump or peripheral nerve stimulator) for the treatment of neuropathic pain.

* Recent use (within 21 days preceding the Treatment Visit [Day 0]) of any topically applied pain medication, such as nonsteroidal anti-inflammatory drugs, menthol, methyl salicylate, local anesthetics (including Lidoderm[R]), steroids or capsaicin products on the painful areas.

* Current use of any investigational drug, or Class 1 anti-arrhythmic drugs (such as tocainide and mexiletine).

* Hypersensitivity to capsaicin (i.e., chili peppers or OTC capsaicin products), local anesthetics, Roxicodone[R], or adhesives.

* Significant ongoing or untreated abnormalities in cardiac, renal, hepatic, or pulmonary function that may interfere either with the ability to complete the study or the evaluation of adverse events.

* Chronic immunosuppression secondary to cytotoxic therapy for malignancy, organ transplant, or Human Immunodeficiency Virus (HIV) infection.

* Unavailability of an effective rescue medication strategy for the subject, such as unwillingness to use opioid analgesics during treatment, or high tolerance to opioids precluding the ability to relieve treatment-associated discomfort with Roxicodone[R] or identified alternative if needed, as judged by the Investigator.

* History or current problem with prescription drug, illicit substance, or alcohol abuse from self report or as judged by the Investigator.

Location and Contact Information:

Arizona Research Center, Phoenix, Arizona, 85023, United States; Dawn Allen 602-863-6363

Arizona                    Colorado   Florida   Utah

Expected Total Enrollment: 300
Study ID Numbers C108
NLM Identifier NCT00061776