Clinical trial NCT01228838: Study of NGX-1998 for the Treatment of Postherpetic Neuralgia
Official title: A Multicenter Randomized, Double-Blind, Controlled Study to Evaluate Safety, Tolerability and Preliminary Efficacy of Two Capsaicin Concentration Variations of NGX-1998 (10% or 20% w/w) in Subjects With Postherpetic Neuralgia (PHN)
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Postherpetic Neuralgia
Pain
Keywords: postherpetic neuralgia
PHN
capsaicin
herpes zoster
shingles
analgesics
neuropathy
Lead sponsor: NeurogesX
Sponsor class: INDUSTRY
First posted: 2010-10-27
Enrollment: 183
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to assess the efficacy, safety and tolerability of NGX-1998 applied for 5 minutes for the treatment of postherpetic neuralgia (PHN).

Detailed description: This study is a 12-week multicenter randomized, double-blind, controlled evaluation of the efficacy, safety and tolerability of NGX-1998 for the treatment of postherpetic neuralgia (PHN). Eligible subjects will have pain from PHN, with average numeric pain rating scale (NPRS) scores during screening of 4 to 9 (inclusive). Painful areas of up to 1500 cm2 will be treated during a single Test Article application. Subjects will be randomly assigned to receive NGX-1998 (10% or 20% w/w) or placebo according to an unequal allocation scheme of 2:2:1. Subjects will also be stratified by gender.

Eligibility criteria: Inclusion Criteria:

* Between 18 and 90 years of age, inclusive.
* Diagnosis of PHN with at least six (6) months of pain since shingles vesicle crusting.
* Average NPRS scores for PHN-associated pain during Days -14 to -4 of 4 to 9, inclusive.
* 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 Test Article Application Visit 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 human chorionic gonadotropin (hCG) pregnancy test, to be performed within 7 days of the Test Article Application 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.
* If breastfeeding, the subject should agree not to breastfeed their child after treatment on the treatment day.
* Be willing and able to comply with protocol requirements for the duration of study participation.
* Subjects must sign an informed consent form for this study approved by the Investigator's Institutional Review Board/Independent Ethics Committee (IRB/IEC).

Exclusion Criteria:

* Concomitant opioid medication, unless orally or transdermally administered and not exceeding a total daily dose of morphine 60 mg/day, or equivalent. Parenteral opioid use is excluded.
* Unavailability of an effective medication for treatment related discomfort for the subject, such as unwillingness to use opioid analgesics during study treatment, or high tolerance to opioids precluding the ability to relieve treatment-associated discomfort.
* Active substance abuse or history of chronic substance abuse within the past year, or prior chronic substance abuse judged likely to recur during the study period.
* Recent use (within 21 days preceding the Test Article Application Visit \[Day 0\]) of any topically applied pain medication on the painful areas.
* Receipt of Qutenza® within 12 months of the Test Article Application Visit (Day 0). Subjects who have received Qutenza® 12 months or more before Test Article Application Visit (Day 0), and who did not respond should also be excluded.
* Participation in another drug research study within 30 days preceding the Test Article Application Visit (Day 0).
* Current use of any Class I anti-arrhythmic drugs or III anti-arrhythmic drugs.
* Diabetes mellitus, unless well-controlled as evidenced by an HBA1c level less than or equal to nine percent (9%).
* A recent history of cardiovascular or cerebrovascular events or unstable hypertension, unless adequately controlled by medication.
* Significant pain of an etiology other than PHN, for example, compression-related neuropathies, fibromyalgia or arthritis.
* Painful PHN areas located on the face, above the hairline of the scalp, and/or in proximity to mucous membranes.
* Any implanted medical device for the treatment of neuropathic pain.
* History of hypersensitivity to capsaicin, local anesthetics or any components of the CTLs, Cleansing Gel or the lidocaine (2.5%) / prilocaine (2.5%) topical anesthetic cream.
* Patients with glucose-6 phosphate dehydrogenase deficiencies.
* Significant ongoing or untreated abnormalities or conditions, including active malignancy defined as treatment required in the last five (5) years, that in the opinion of the Investigator would interfere with the ability to complete the study or the evaluation of AEs.
* Patients with congenital or idiopathic methemoglobinemia.
* Recent history of a significant medical-surgical intervention in the judgment of the Investigator; examples include but are not limited to major surgery or percutaneous angioplasty/coronary artery stent placement within the past 3 months, and receipt of immunosuppressive therapy within 3 months, prior to the Test Article Application Visit \[Day 0\].
* Evidence of cognitive impairment including dementia that may interfere with subject's ability to complete daily pain diaries requiring subject's recall of average PHN pain level in the past 24 hours.

Primary outcomes:
measure: Percent change from baseline in the "average pain for the past 24 hours" NPRS score during Weeks 2-8.
timeFrame: Weeks 2-8
Secondary outcomes:
measure: Absolute change and percent change from baseline in the "average pain for the past 24 hours" NPRS score at Week 8 and 12
timeFrame: Week 8 and Week 12
measure: Absolute change and percent change from baseline in the "average pain for the past 24 hours" NPRS score during Weeks 2-12.
timeFrame: Weeks 2-12
measure: Proportion of subjects with at least a 30% decrease from baseline in their "average pain for the past 24 hours" NPRS during Weeks 2-8, Weeks 2-12, at Week 8 and Week 12.
timeFrame: Weeks 2-12
measure: Proportion of subjects with at least a 2 unit decrease from baseline in their "average pain for the past 24 hours" NPRS during Weeks 2-8, Weeks 2-12, at Week 8 and Week 12.
timeFrame: Week 8 and Week 12
Other outcomes:
Locations:
city: Huntsville
country: United States
facility: NeurogesX Investigational Site
state: Alabama
city: Tucson
country: United States
facility: NeurogesX Investigational Site
state: Arizona
city: Irvine
country: United States
facility: NeurogesX Investigational Site
state: California
city: La Jolla
country: United States
facility: NeurogesX Investigational Site
state: California
city: Napa
country: United States
facility: NeurogesX Investigational Site
state: California
city: San Francisco
country: United States
facility: NeurogesX Investigational Site
state: California
city: Santa Monica
country: United States
facility: NeurogesX Investigational Site
state: California
city: New Port Richey
country: United States
facility: NeurogesX Investigational Site
state: Florida
city: North Palm Beach
country: United States
facility: NeurogesX Investigational Site
state: Florida
city: Sarasota
country: United States
facility: NeurogesX Investigational Site
state: Florida
city: St. Petersburg
country: United States
facility: NeurogesX Investigational Site
state: Florida
city: Marietta
country: United States
facility: NeurogesX Investigational Site
state: Georgia
city: Boise
country: United States
facility: NeurogesX Investigational Site
state: Idaho
city: Bloomington
country: United States
facility: NeurogesX Investigational Site
state: Illinois
city: West Des Moines
country: United States
facility: NeurogesX Investigational Site
state: Iowa
city: Kansas City
country: United States
facility: NeurogesX Investigational Site
state: Kansas
city: Lexington
country: United States
facility: NeurogesX Investigational Site
state: Kentucky
city: Shreveport
country: United States
facility: NeurogesX Investigational Site
state: Louisiana
city: Hyannis
country: United States
facility: NeurogesX Investigational Site
state: Massachusetts
city: Ann Arbor
country: United States
facility: NeurogesX Investigational Site
state: Michigan
city: Minneapolis
country: United States
facility: NeurogesX Investigational Site
state: Minnesota
city: Hattiesburg
country: United States
facility: NeurogesX Investigational Site
state: Mississippi
city: Albany
country: United States
facility: NeurogesX Investigational Site
state: New York
city: Rochester
country: United States
facility: NeurogesX Investigational Site
state: New York
city: Hickory
country: United States
facility: NeurogesX Investigational Site
state: North Carolina
city: Winston-Salem
country: United States
facility: NeurogesX Investigational Site
state: North Carolina
city: Portland
country: United States
facility: NeurogesX Investigational Site
state: Oregon
city: Altoona
country: United States
facility: NeurogesX Investigational Site
state: Pennsylvania
city: San Antonio
country: United States
facility: NeurogesX Investigational Site
state: Texas
city: Webster
country: United States
facility: NeurogesX Investigational Site
state: Texas
city: Salt Lake City
country: United States
facility: NeurogesX Investigational Site
state: Utah
city: Richmond
country: United States
facility: NeurogesX Investigational Site
state: Virginia
city: Seattle
country: United States
facility: NeurogesX Investigational Site
state: Washington
city: Wenatchee
country: United States
facility: NeurogesX Investigational Site
state: Washington
city: Madison
country: United States
facility: NeurogesX Investigational Site
state: Wisconsin
Study officials:
affiliation: NeurogesX
name: Trudy Vanhove, MD, PhD, MBA
role: STUDY_DIRECTOR
References: