Back to resultsSafety/Efficacy Study of Retigabine vs. Placebo in Post-Herpetic Neuralgia (PHN)
Primary Purpose
Postherpetic Neuralgia
Status
Completed
Phase
Phase 2
Locations
International
Study Type
Interventional
Intervention
Retigabine
Placebo
Sponsored by
About this trial
This is an interventional treatment trial for Postherpetic Neuralgia focused on measuring Postherpetic Neuralgia, PHN, Shingles,
Eligibility Criteria
Inclusion Criteria:
- Ability to provide informed consent
- Male or female subjects
- 18-85 years of age
- PHN for more than 6 months after the healing of herpes zoster skin rash
- Has a pain score at screening and randomization that qualifies
Exclusion Criteria:
- Other significant pain that may potentially confound PHN pain assessment
- Previous neurolytic or neurosurgical therapy for PHN
- Subject has evidence of a progressive central nervous system (CNS) disease (e.g. CNS lupus, tumors, multiple sclerosis, Alzheimer's), lesion, or encephalopathy
- Significant psychiatric or neuropsychiatric disorders including but not limited to severe depression, bipolar disorder or schizophrenia spectrum disorder, history of suicide attempt, or recent history of suicidal ideation
- Has clinically significant abnormalities on physical examination, vital signs, ECG, or laboratory tests at the screening visit
Sites / Locations
Arms of the Study
Arm 1
Arm 2
Arm Type
Experimental
Placebo Comparator
Arm Label
1
2
Arm Description
Retigabine
Placebo
Outcomes
Primary Outcome Measures
Primary Endpoint Will be the Change From Baseline in Average Pain Score Over the Last 7 Days of the Maintenance Phase.
Change from Baseline (BL) was calculated as the value of the average diary pain score for the last 7 days of the MP minus the value of the average pain score at BL (post wash-out period, including the average of the last 7 available entries prior to/including the diary pain measurement on Titration Day 0). Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point Numerical Rating Scale (NRS): 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Secondary Outcome Measures
Change From Baseline to Weeks 2 and 4 of the Maintenance Phase in Mean In-clinic Pain Assessment
Participants rated their pain during the previous 24 hours at all clinic visits using an 11-point Numerical Rating Scale (NRS): 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain (10=worst possible pain). Change in In-clinic Pain Assessment was calculated by subtracting the average score on the NRS at Week 2 and Week 4 (values for each week were observed cases) of the MP from the average score on the NRS at Baseline (the last non-missing measurement prior to taking study drug).
Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP)
Participants recorded the number of acetaminophen tablets taken during the previous 24 hours in a participant diary. Rescue medication was summarized as the mean number of doses taken per day during each week of the Maintenance Phase (MP) and the mean number of doses taken during all MP weeks.
Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP)
Least square mean (LSM) of pain intensity was calculated from the NRS score entered by the participants in their diaries at each week during the MP. Participants rated their pain during the previous 24 hours at all clinic visits using an NRS: 0, no pain; 1-3, mild; 4-6, moderate; 7-10 (worst possible pain), severe pain. Change from Baseline was calculated by subtracting the value of the average of the LSM of the NRS score at each week during the MP (the last 7 available diary entries in the MP were used, provided at least 3 existed) from the average Baseline value of the LSM of the NRS score.
Number of Participants Classified as Responders, With a 50% and 30% Pain Reduction From Baseline to the Last 7 Days of the Maintenance Phase
Responders were defined as participants achieving a mean >=50% or >=30% pain reduction based on the NRS score from Baseline to the last 7 days of the MP. Those participants who did not have at least 3 diary entries in the MP, those who withdrew during the Titration Phase (TP), and non-completers (NC: who did not complete the study) were classified as non-responders. The number of responders and responders including non-completers from Baseline to the last 7 days of the MP were reported.
Change From Baseline to the End of the MP (Included All Participants Who Completed Week 4 of the MP and Who Terminated Early During the MP) in Medical Outcomes Study (MOS) Sleep Scale Scores
Change from BL (average value of MOS Sleep Scale score including Overall Sleep Problem [OSP] Index at end of MP minus average BL value) to the end of the MP was summarized for the OSP Index, in addition to the following subscales of the MOS Sleep Scale: Sleep Disturbance; Sleep Adequacy; Snoring; Awakening with Shortness of Breath or with a Headache; Somnolence; and Optimal Sleep. Each item was transformed to a scale with a range of 0-100. For each subscale, except Optimal Sleep, higher scores indicate a greater level of what was being measured (i.e., more snoring, more sleep adequacy, etc.).
Change From Baseline to the End of the MP (Included All Participants Who Completed Week 4 of the MP and Who Terminated Early During the MP) in Sleep Quantity
Change from Baseline in sleep quantity was calculated by subtracting the average value of sleep quantity, calculated in hours, at the end of the MP from the average Baseline value.
Number of Participants With the Indicated Change From Baseline to the End of the Maintenance Phase in Optimal Sleep Based on the Sleep Quantity Domain of the MOS Sleep Scale
Optimal Sleep was based on the Sleep Quantity domain of the MOS Sleep Scale and included the options of "Yes" if sleep quantity was 7-8 hours, and "No" otherwise. "Improved" indicated a change in response of no at baseline to yes at the end of the MP, "Same" indicated no change in response, and "Worse" indicated a change in response from yes at baseline to no at the end of the MP.
Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC)
For the PGIC assessment, participants were asked to assess their overall status since they initiated the study drug to the end of the Maintenance Phase using a 7-point categorical scale: 1=very much improved, 2=much improved, 3=minimally improved, 4=no change, 5=minimally worse, 6=much worse, and 7=very much worse. All participants who completed Week 4 of the Maintenance Phase and participants who terminated early during the Maintenance Phase were assessed.
Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase
The TSQM assessed the participant's overall satisfaction with treatment, including subscales to assess effectiveness, side effects, convenience, and global satisfaction. Raw scores from the scale were transformed into a numeric scale ranging from 0 to 100, where higher scores indicated greater satisfaction with treatment. TSQM was reported at the end of the MP. Participants who completed Week 4 of the MP and who terminated early during the MP were assessed.
Scores on the Brief Pain Inventory-Short Form (BPI-SF) at the End of the MP for All Participants Who Completed Week-4 of the MP and Who Terminated Early During the MP
The BPI-SF assessed pain intensity, pain relief from medication, and pain interference with function over the previous 24 hours. Pain intensity was assessed by the mean of 4 intensity items rated on a 0-10 categorical scale: 0=no pain, 10=pain as bad as you can imagine. Pain interference was assessed by determining the mean of the 7 interference items on a 0-10 categorical scale ranging from 0=does not interfere to 10=completely interferes. The level of pain relief provided by treatment was assessed on an 11-point categorical scale ranging from 0% to 100%
Scores on the Medical Outcomes Short Form-36 (SF-36) at the End of the MP for All Participants Who Completed Week 4 of the MP and Who Terminated Early During the MP
Least square (LS) mean calculated based on participant's assessment of SF-36,a quality of life questionnaire consisting of 36 items grouped into 8 domains. These 8 domains further grouped into 2 overall summary measures,physical health and mental health. Higher scores on SF-36 represented better state of health. Physical/mental components summarized the data of all the physical/mental domains of SF-36 and higher scores represented better state of health.
Scores for Reported Health Transition at the End of the MP for All Participants Who Completed Week 4 of the MP and Who Terminated Early During the MP
The least square (LS) mean score for reported health transition was calculated based on the scores (ranging from 1 to 5) given by the participant in answer to the following question: "Compared to 1 year ago, how would you rate your health in general now?". Lower numbers represent a better state of health.
Number of Participants With the Indicated Responses at Baseline to the Question: "How Painful Was the Affected Side Compared to the Opposite Side?" in an Assessment of Tactile Allodynia
At Baseline, the investigator conducted the Neuropathic Pain Physical Examination (NPPE) to examine hyperalgesia and allodynia (tactile and cold). Tactile allodynia was assessed with a foam brush, based on the question:"How painful was the affected side compared to the opposite side?".
Number of Participants With the Indicated Responses at Baseline to the Questions of "Is it Cool?" and "Is it Painful?" in an Assessment of Cold Threshold and Allodynia
At Baseline the investigator conducted the NPPE to examine hyperalgesia and allodynia (tactile and cold). Cold threshold and allodynia was assessed to determine if a metal bar felt cool and if it felt painful, based on the questions:"Is it cool?" and "Is it painful?"
Number of Subjects With the Indicated Responses at Baseline to the Questions: "How Sharp Was the Affected Side Compared to the Opposite Side?" and "How Painfule Was the Affected Side Compared to the Opposite Side?" in an Assessment of Hyperalgesia
At Baseline the investigator conducted the NPPE to examine hyperalgesia and allodynia (tactile and cold). Hyperalgesia is defined as increased sensitivity to pain, which may be caused by damage to peripheral nerves. It was assessed with a pinprick brush, based on the questions: "How sharp was the affected side compared to the opposite side?" and "How painfule was the affected side compared to the opposite side?"
Number of Participants With the Indicated Responses at the End of the MP to the Question: "How Painful Was the Affected Side Compared to the Opposite Side?" in an Assessment of Tactile Allodynia
At the end of the MP, the investigator conducted the NPPE (an examination of the effect of retigabine on sensory abnormalities) to examine hyperalgesia and allodynia (tactile and cold). Tactile allodynia was assessed with a foam brush, based on the question:"How painful was the affected side compared to the opposite side?" End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
Number of Participants With the Indicated Responses at the End of the MP to the Questions of "Is it Cool?" and "Is it Painful?" in an Assessment of Cold Threshold and Allodynia
At the end of the MP, the investigator conducted the NPPE (an examination of the effect of retigabine on sensory abnormalities) to examine hyperalgesia and allodynia (tactile and cold). Cold threshold and allodynia was assessed to determine if a metal bar felt cool and if it felt painful, based on the questions:"Is it cool?" and "Is it painful?"
Number of Participants With Indicated Responses at the End of the MP to the Questions: "How Sharp Was the Affected Side Compared to the Opposite Side?" and "How Painful Was the Affected Side Compared to the Opposite Side?" in an Assessment of Hyperalgesia
At the end of the MP, the investigator conducted the NPPE (an examination of the effect of retigabine on sensory abnormalities) to examine hyperalgesia and allodynia (tactile and cold). Hyperalgesia is defined as increased sensitivity to pain, which may be caused by damage to peripheral nerves. It was assessed with a pinprick brush, based on the questions:"How sharp was the affected side compared to the opposite side?" and How painful was the affected side compared to the opposite side?"
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) Subtype "Irritable Nociceptors"
Participants were stratified into four different PHN subtypes based on the NPPE. Participants with pain, abnormal sensitization of the specific receptor (irritable nociceptors), and with minimal sensory loss were stratified in the"irritable nociceptors" subtype. Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point NRS: 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) Subtype"Deafferentation Type 1 (D Type 1)"
Participants stratified into 4 different PHN subtypes based on NPPE. Participants with marked sensory loss associated with severe burning pain upon slight mechanical stimuli (allodynia) were stratified in the "deafferentation type 1" subtype. Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point NRS: 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) Subtype "Deafferentation Type 2 (D Type 2)"
Participants stratified into 4 different PHN subtypes based on NPPE. Participants with marked sensory loss and severe spontaneous burning pain without allodynia associated with reorganization of central nerve fibers were stratified in the "deafferentation type 2" subtype. Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point NRS: 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) Subtype "Unclassifiable"
Participants stratified into 4 different PHN subtypes based on NPPE. Participants who could not be specifically differentiated in any of the other three subtypes were stratified as "unclassifiable" meaning that the participants could not be classified into any of the predefined PHN subtypes. Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point NRS: 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Full Information
NCT ID
NCT00612105
First Posted
January 25, 2008
Last Updated
April 6, 2018
Sponsor
Bausch Health Americas, Inc.
1. Study Identification
Unique Protocol Identification Number
NCT00612105
Brief Title
Safety/Efficacy Study of Retigabine vs. Placebo in Post-Herpetic Neuralgia (PHN)
Official Title
A Randomized, Double-Blind, Placebo-Controlled, Phase 2a Proof-of-Concept Study to Evaluate the Efficacy of Maximally Tolerated Doses of Retigabine vs. Placebo in Reducing the Pain Associated With Post-Herpetic Neuralgia
Study Type
Interventional
2. Study Status
Record Verification Date
April 2018
Overall Recruitment Status
Completed
Study Start Date
October 2007 (undefined)
Primary Completion Date
May 2009 (Actual)
Study Completion Date
December 2009 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Bausch Health Americas, Inc.
4. Oversight
Data Monitoring Committee
No
5. Study Description
Brief Summary
The purpose of the study is to evaluate the efficacy of retigabine vs. placebo in reducing pain associated with post-herpetic neuralgia.
Detailed Description
This is a Phase 2a proof of concept study evaluating the safety/efficacy of retigabine vs. placebo in patients with post-herpetic neuralgia. After screening, patients will enter a maximum 6 week titration period followed by a 4 week maintenance period and a 3 week taper phase.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Postherpetic Neuralgia
Keywords
Postherpetic Neuralgia, PHN, Shingles,
7. Study Design
Primary Purpose
Treatment
Study Phase
Phase 2
Interventional Study Model
Parallel Assignment
Masking
ParticipantCare ProviderInvestigatorOutcomes Assessor
Allocation
Randomized
Enrollment
187 (Actual)
8. Arms, Groups, and Interventions
Arm Title
1
Arm Type
Experimental
Arm Description
Retigabine
Arm Title
2
Arm Type
Placebo Comparator
Arm Description
Placebo
Intervention Type
Drug
Intervention Name(s)
Retigabine
Intervention Description
150mg/day up to 900mg/day
Intervention Type
Drug
Intervention Name(s)
Placebo
Intervention Description
daily
Primary Outcome Measure Information:
Title
Primary Endpoint Will be the Change From Baseline in Average Pain Score Over the Last 7 Days of the Maintenance Phase.
Description
Change from Baseline (BL) was calculated as the value of the average diary pain score for the last 7 days of the MP minus the value of the average pain score at BL (post wash-out period, including the average of the last 7 available entries prior to/including the diary pain measurement on Titration Day 0). Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point Numerical Rating Scale (NRS): 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Time Frame
Baseline and Week 4 (Maintenance Phase-MP)
Secondary Outcome Measure Information:
Title
Change From Baseline to Weeks 2 and 4 of the Maintenance Phase in Mean In-clinic Pain Assessment
Description
Participants rated their pain during the previous 24 hours at all clinic visits using an 11-point Numerical Rating Scale (NRS): 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain (10=worst possible pain). Change in In-clinic Pain Assessment was calculated by subtracting the average score on the NRS at Week 2 and Week 4 (values for each week were observed cases) of the MP from the average score on the NRS at Baseline (the last non-missing measurement prior to taking study drug).
Time Frame
Baseline and Weeks 2 and 4 (Maintenance Phase - MP)
Title
Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP)
Description
Participants recorded the number of acetaminophen tablets taken during the previous 24 hours in a participant diary. Rescue medication was summarized as the mean number of doses taken per day during each week of the Maintenance Phase (MP) and the mean number of doses taken during all MP weeks.
Time Frame
Weeks 1, 2, 3, and 4 Maintenance Phase
Title
Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP)
Description
Least square mean (LSM) of pain intensity was calculated from the NRS score entered by the participants in their diaries at each week during the MP. Participants rated their pain during the previous 24 hours at all clinic visits using an NRS: 0, no pain; 1-3, mild; 4-6, moderate; 7-10 (worst possible pain), severe pain. Change from Baseline was calculated by subtracting the value of the average of the LSM of the NRS score at each week during the MP (the last 7 available diary entries in the MP were used, provided at least 3 existed) from the average Baseline value of the LSM of the NRS score.
Time Frame
Baseline and Weeks 1, 2, 3, and 4 (MP)
Title
Number of Participants Classified as Responders, With a 50% and 30% Pain Reduction From Baseline to the Last 7 Days of the Maintenance Phase
Description
Responders were defined as participants achieving a mean >=50% or >=30% pain reduction based on the NRS score from Baseline to the last 7 days of the MP. Those participants who did not have at least 3 diary entries in the MP, those who withdrew during the Titration Phase (TP), and non-completers (NC: who did not complete the study) were classified as non-responders. The number of responders and responders including non-completers from Baseline to the last 7 days of the MP were reported.
Time Frame
Baseline and Week 4 Maintenance Phase (MP)
Title
Change From Baseline to the End of the MP (Included All Participants Who Completed Week 4 of the MP and Who Terminated Early During the MP) in Medical Outcomes Study (MOS) Sleep Scale Scores
Description
Change from BL (average value of MOS Sleep Scale score including Overall Sleep Problem [OSP] Index at end of MP minus average BL value) to the end of the MP was summarized for the OSP Index, in addition to the following subscales of the MOS Sleep Scale: Sleep Disturbance; Sleep Adequacy; Snoring; Awakening with Shortness of Breath or with a Headache; Somnolence; and Optimal Sleep. Each item was transformed to a scale with a range of 0-100. For each subscale, except Optimal Sleep, higher scores indicate a greater level of what was being measured (i.e., more snoring, more sleep adequacy, etc.).
Time Frame
Baseline and End of Maintenance Phase (MP) (Week 4).
Title
Change From Baseline to the End of the MP (Included All Participants Who Completed Week 4 of the MP and Who Terminated Early During the MP) in Sleep Quantity
Description
Change from Baseline in sleep quantity was calculated by subtracting the average value of sleep quantity, calculated in hours, at the end of the MP from the average Baseline value.
Time Frame
Baseline and End of Maintenance Phase (MP) (Week 4).
Title
Number of Participants With the Indicated Change From Baseline to the End of the Maintenance Phase in Optimal Sleep Based on the Sleep Quantity Domain of the MOS Sleep Scale
Description
Optimal Sleep was based on the Sleep Quantity domain of the MOS Sleep Scale and included the options of "Yes" if sleep quantity was 7-8 hours, and "No" otherwise. "Improved" indicated a change in response of no at baseline to yes at the end of the MP, "Same" indicated no change in response, and "Worse" indicated a change in response from yes at baseline to no at the end of the MP.
Time Frame
Baseline and End of Maintenance Phase (MP) (Week 4).
Title
Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC)
Description
For the PGIC assessment, participants were asked to assess their overall status since they initiated the study drug to the end of the Maintenance Phase using a 7-point categorical scale: 1=very much improved, 2=much improved, 3=minimally improved, 4=no change, 5=minimally worse, 6=much worse, and 7=very much worse. All participants who completed Week 4 of the Maintenance Phase and participants who terminated early during the Maintenance Phase were assessed.
Time Frame
Baseline to the end of Maintenance Phase (MP) (Week 4)
Title
Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase
Description
The TSQM assessed the participant's overall satisfaction with treatment, including subscales to assess effectiveness, side effects, convenience, and global satisfaction. Raw scores from the scale were transformed into a numeric scale ranging from 0 to 100, where higher scores indicated greater satisfaction with treatment. TSQM was reported at the end of the MP. Participants who completed Week 4 of the MP and who terminated early during the MP were assessed.
Time Frame
End of Maintenance Phase (MP) (Week 4)
Title
Scores on the Brief Pain Inventory-Short Form (BPI-SF) at the End of the MP for All Participants Who Completed Week-4 of the MP and Who Terminated Early During the MP
Description
The BPI-SF assessed pain intensity, pain relief from medication, and pain interference with function over the previous 24 hours. Pain intensity was assessed by the mean of 4 intensity items rated on a 0-10 categorical scale: 0=no pain, 10=pain as bad as you can imagine. Pain interference was assessed by determining the mean of the 7 interference items on a 0-10 categorical scale ranging from 0=does not interfere to 10=completely interferes. The level of pain relief provided by treatment was assessed on an 11-point categorical scale ranging from 0% to 100%
Time Frame
End of Maintenance Phase (MP) (Week 4)
Title
Scores on the Medical Outcomes Short Form-36 (SF-36) at the End of the MP for All Participants Who Completed Week 4 of the MP and Who Terminated Early During the MP
Description
Least square (LS) mean calculated based on participant's assessment of SF-36,a quality of life questionnaire consisting of 36 items grouped into 8 domains. These 8 domains further grouped into 2 overall summary measures,physical health and mental health. Higher scores on SF-36 represented better state of health. Physical/mental components summarized the data of all the physical/mental domains of SF-36 and higher scores represented better state of health.
Time Frame
End of Maintenance Phase (MP) (Week 4)
Title
Scores for Reported Health Transition at the End of the MP for All Participants Who Completed Week 4 of the MP and Who Terminated Early During the MP
Description
The least square (LS) mean score for reported health transition was calculated based on the scores (ranging from 1 to 5) given by the participant in answer to the following question: "Compared to 1 year ago, how would you rate your health in general now?". Lower numbers represent a better state of health.
Time Frame
End of maintenance Phase (MP) (Week 4)
Title
Number of Participants With the Indicated Responses at Baseline to the Question: "How Painful Was the Affected Side Compared to the Opposite Side?" in an Assessment of Tactile Allodynia
Description
At Baseline, the investigator conducted the Neuropathic Pain Physical Examination (NPPE) to examine hyperalgesia and allodynia (tactile and cold). Tactile allodynia was assessed with a foam brush, based on the question:"How painful was the affected side compared to the opposite side?".
Time Frame
Baseline Phase (Day -7 to Randomization Day 0)
Title
Number of Participants With the Indicated Responses at Baseline to the Questions of "Is it Cool?" and "Is it Painful?" in an Assessment of Cold Threshold and Allodynia
Description
At Baseline the investigator conducted the NPPE to examine hyperalgesia and allodynia (tactile and cold). Cold threshold and allodynia was assessed to determine if a metal bar felt cool and if it felt painful, based on the questions:"Is it cool?" and "Is it painful?"
Time Frame
Timeframe: Baseline Phase (Day -7 to Randomization Day 0)
Title
Number of Subjects With the Indicated Responses at Baseline to the Questions: "How Sharp Was the Affected Side Compared to the Opposite Side?" and "How Painfule Was the Affected Side Compared to the Opposite Side?" in an Assessment of Hyperalgesia
Description
At Baseline the investigator conducted the NPPE to examine hyperalgesia and allodynia (tactile and cold). Hyperalgesia is defined as increased sensitivity to pain, which may be caused by damage to peripheral nerves. It was assessed with a pinprick brush, based on the questions: "How sharp was the affected side compared to the opposite side?" and "How painfule was the affected side compared to the opposite side?"
Time Frame
Baseline Phase (Day -7 to Randomization Day 0)
Title
Number of Participants With the Indicated Responses at the End of the MP to the Question: "How Painful Was the Affected Side Compared to the Opposite Side?" in an Assessment of Tactile Allodynia
Description
At the end of the MP, the investigator conducted the NPPE (an examination of the effect of retigabine on sensory abnormalities) to examine hyperalgesia and allodynia (tactile and cold). Tactile allodynia was assessed with a foam brush, based on the question:"How painful was the affected side compared to the opposite side?" End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
Time Frame
End of Maintenance Phase (MP) (Week 4)
Title
Number of Participants With the Indicated Responses at the End of the MP to the Questions of "Is it Cool?" and "Is it Painful?" in an Assessment of Cold Threshold and Allodynia
Description
At the end of the MP, the investigator conducted the NPPE (an examination of the effect of retigabine on sensory abnormalities) to examine hyperalgesia and allodynia (tactile and cold). Cold threshold and allodynia was assessed to determine if a metal bar felt cool and if it felt painful, based on the questions:"Is it cool?" and "Is it painful?"
Time Frame
End of Maintenance Phase (MP) (Week 4)
Title
Number of Participants With Indicated Responses at the End of the MP to the Questions: "How Sharp Was the Affected Side Compared to the Opposite Side?" and "How Painful Was the Affected Side Compared to the Opposite Side?" in an Assessment of Hyperalgesia
Description
At the end of the MP, the investigator conducted the NPPE (an examination of the effect of retigabine on sensory abnormalities) to examine hyperalgesia and allodynia (tactile and cold). Hyperalgesia is defined as increased sensitivity to pain, which may be caused by damage to peripheral nerves. It was assessed with a pinprick brush, based on the questions:"How sharp was the affected side compared to the opposite side?" and How painful was the affected side compared to the opposite side?"
Time Frame
End of Maintenance Phase (MP) (Week 4)
Title
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) Subtype "Irritable Nociceptors"
Description
Participants were stratified into four different PHN subtypes based on the NPPE. Participants with pain, abnormal sensitization of the specific receptor (irritable nociceptors), and with minimal sensory loss were stratified in the"irritable nociceptors" subtype. Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point NRS: 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Time Frame
Baseline and Week 4 Maintenance Phase (MP)
Title
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) Subtype"Deafferentation Type 1 (D Type 1)"
Description
Participants stratified into 4 different PHN subtypes based on NPPE. Participants with marked sensory loss associated with severe burning pain upon slight mechanical stimuli (allodynia) were stratified in the "deafferentation type 1" subtype. Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point NRS: 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Time Frame
Baseline and Week 4 Maintenance Phase (MP)
Title
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) Subtype "Deafferentation Type 2 (D Type 2)"
Description
Participants stratified into 4 different PHN subtypes based on NPPE. Participants with marked sensory loss and severe spontaneous burning pain without allodynia associated with reorganization of central nerve fibers were stratified in the "deafferentation type 2" subtype. Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point NRS: 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Time Frame
Baseline and Week 4 Maintenance phase (MP)
Title
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) Subtype "Unclassifiable"
Description
Participants stratified into 4 different PHN subtypes based on NPPE. Participants who could not be specifically differentiated in any of the other three subtypes were stratified as "unclassifiable" meaning that the participants could not be classified into any of the predefined PHN subtypes. Based on their pain experienced during the previous 24 hours, participants assessed their pain every evening at bedtime in an electronic diary by choosing the appropriate number on an 11-point NRS: 0, no pain; 1 to 3, mild; 4 to 6, moderate; 7 to 10, severe pain.
Time Frame
Baseline and Week 4 Maintenance Phase (MP)
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
85 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Ability to provide informed consent
Male or female subjects
18-85 years of age
PHN for more than 6 months after the healing of herpes zoster skin rash
Has a pain score at screening and randomization that qualifies
Exclusion Criteria:
Other significant pain that may potentially confound PHN pain assessment
Previous neurolytic or neurosurgical therapy for PHN
Subject has evidence of a progressive central nervous system (CNS) disease (e.g. CNS lupus, tumors, multiple sclerosis, Alzheimer's), lesion, or encephalopathy
Significant psychiatric or neuropsychiatric disorders including but not limited to severe depression, bipolar disorder or schizophrenia spectrum disorder, history of suicide attempt, or recent history of suicidal ideation
Has clinically significant abnormalities on physical examination, vital signs, ECG, or laboratory tests at the screening visit
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
David Lineberry
Organizational Affiliation
Sponsor GmbH
Official's Role
Study Director
Facility Information:
City
Birmingham
State/Province
Alabama
ZIP/Postal Code
35215
Country
United States
City
Mesa
State/Province
Arizona
ZIP/Postal Code
85210
Country
United States
City
Tucson
State/Province
Arizona
ZIP/Postal Code
85741
Country
United States
City
Little Rock
State/Province
Arkansas
ZIP/Postal Code
72205
Country
United States
City
Garden Grove
State/Province
California
ZIP/Postal Code
92845
Country
United States
City
La Jolla
State/Province
California
ZIP/Postal Code
92037
Country
United States
City
San Diego
State/Province
California
ZIP/Postal Code
92128
Country
United States
City
Westlake Village
State/Province
California
ZIP/Postal Code
91361
Country
United States
City
Orlando
State/Province
Florida
ZIP/Postal Code
32806
Country
United States
City
Sarasota
State/Province
Florida
ZIP/Postal Code
34243
Country
United States
City
Tampa
State/Province
Florida
ZIP/Postal Code
33613
Country
United States
City
West Palm Beach
State/Province
Florida
ZIP/Postal Code
33407
Country
United States
City
Atlanta
State/Province
Georgia
ZIP/Postal Code
30308
Country
United States
City
Atlanta
State/Province
Georgia
ZIP/Postal Code
30309
Country
United States
City
Evansville
State/Province
Indiana
ZIP/Postal Code
47714
Country
United States
City
Overland Park
State/Province
Kansas
ZIP/Postal Code
66211
Country
United States
City
Lexington
State/Province
Kentucky
ZIP/Postal Code
40503
Country
United States
City
Shreveport
State/Province
Louisiana
ZIP/Postal Code
71103
Country
United States
City
Bay City
State/Province
Michigan
ZIP/Postal Code
48706
Country
United States
City
Detroit
State/Province
Michigan
ZIP/Postal Code
48201
Country
United States
City
Hattiesburg
State/Province
Mississippi
ZIP/Postal Code
39401
Country
United States
City
Saint Louis
State/Province
Missouri
ZIP/Postal Code
63117
Country
United States
City
Saint Louis
State/Province
Missouri
ZIP/Postal Code
63141
Country
United States
City
Toms River
State/Province
New Jersey
ZIP/Postal Code
8755
Country
United States
City
New York
State/Province
New York
ZIP/Postal Code
10004
Country
United States
City
Raleigh
State/Province
North Carolina
ZIP/Postal Code
27607
Country
United States
City
Tabor City
State/Province
North Carolina
ZIP/Postal Code
28463
Country
United States
City
Winston-Salem
State/Province
North Carolina
ZIP/Postal Code
27103
Country
United States
City
Fargo
State/Province
North Dakota
ZIP/Postal Code
58104
Country
United States
City
Cleveland
State/Province
Ohio
ZIP/Postal Code
44195
Country
United States
City
Mogadore
State/Province
Ohio
ZIP/Postal Code
44260
Country
United States
City
Allentown
State/Province
Pennsylvania
ZIP/Postal Code
18103
Country
United States
City
Bridgeville
State/Province
Pennsylvania
ZIP/Postal Code
15017
Country
United States
City
Charleston
State/Province
South Carolina
ZIP/Postal Code
29412
Country
United States
City
Little River
State/Province
South Carolina
ZIP/Postal Code
29566
Country
United States
City
North Myrtle Beach
State/Province
South Carolina
ZIP/Postal Code
29582
Country
United States
City
Nashville
State/Province
Tennessee
ZIP/Postal Code
37215
Country
United States
City
Austin
State/Province
Texas
ZIP/Postal Code
78756
Country
United States
City
San Antonio
State/Province
Texas
ZIP/Postal Code
78229
Country
United States
City
Sugar Land
State/Province
Texas
ZIP/Postal Code
77479
Country
United States
City
Midvale
State/Province
Utah
ZIP/Postal Code
84047-1761
Country
United States
City
Port Elizabeth
State/Province
Eastern Cape
ZIP/Postal Code
6001
Country
South Africa
City
Bloemfontein
State/Province
Free State
ZIP/Postal Code
9300
Country
South Africa
City
Belville
State/Province
Western Cape
ZIP/Postal Code
7530
Country
South Africa
City
George
State/Province
Western Cape
ZIP/Postal Code
6529
Country
South Africa
12. IPD Sharing Statement
Learn more about this trial
Safety/Efficacy Study of Retigabine vs. Placebo in Post-Herpetic Neuralgia (PHN)
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