Postherpetic Neuralgia
Conditions
Keywords
Postherpetic Neuralgia, PHN, Shingles,
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.
Interventions
DRUGRetigabine
150mg/day up to 900mg/day
DRUGPlacebo
daily
Sponsors
Bausch Health Americas, Inc.
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 85 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Primary Endpoint Will be the Change From Baseline in Average Pain Score Over the Last 7 Days of the Maintenance Phase. | Baseline and Week 4 (Maintenance Phase-MP) | 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
| Measure | Time frame | Description |
|---|---|---|
| Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Weeks 1, 2, 3, and 4 Maintenance Phase | 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) | Baseline and Weeks 1, 2, 3, and 4 (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 | Baseline and Week 4 Maintenance Phase (MP) | 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 | Baseline and End of Maintenance Phase (MP) (Week 4). | 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 | Baseline and End of Maintenance Phase (MP) (Week 4). | 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 | Baseline and End of Maintenance Phase (MP) (Week 4). | 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 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 | End of Maintenance Phase (MP) (Week 4) | 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 the Indicated Overall Patient Global Impression of Change (PGIC) | Baseline to the end of Maintenance Phase (MP) (Week 4) | 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 | End of Maintenance Phase (MP) (Week 4) | 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 | End of Maintenance Phase (MP) (Week 4) | 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% |
| Change From Baseline to Weeks 2 and 4 of the Maintenance Phase in Mean In-clinic Pain Assessment | Baseline and Weeks 2 and 4 (Maintenance Phase - MP) | 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). |
| 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 | End of maintenance Phase (MP) (Week 4) | 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 | Baseline Phase (Day -7 to Randomization Day 0) | 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 | Timeframe: Baseline Phase (Day -7 to Randomization Day 0) | 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 | Baseline Phase (Day -7 to Randomization Day 0) | 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 | End of Maintenance Phase (MP) (Week 4) | 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 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 | End of Maintenance Phase (MP) (Week 4) | 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 | Baseline and Week 4 Maintenance Phase (MP) | 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 theirritable 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) SubtypeDeafferentation Type 1 (D Type 1) | Baseline and Week 4 Maintenance Phase (MP) | 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) | Baseline and Week 4 Maintenance phase (MP) | 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 | Baseline and Week 4 Maintenance Phase (MP) | 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. |
| 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 | End of Maintenance Phase (MP) (Week 4) | 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. |
Countries
South Africa, United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| 1: Retigabine Arm Description: Participants started on a total daily dose of 150 milligrams (mg) and were titrated to their maximum tolerated dose (MTD) up to a maximum of 900 mg daily using retigabine 50 mg and/or 100 mg tablets. The dose was increased by 150 mg each week and administered 3 times daily (TID) in equally divided doses. In the Maintenance Phase, retigabine was administered in equally divided doses to maintain the participant's MTD. Participants with moderate to severe side effects during the first week at their MTD and who had attained at least dose level 3 (450 mg) were allowed a one level dose reduction (150 mg). Participants unable to maintain the MTD discontinued the medication. In the Taper Phase, the dose was reduced by one-third during each of the first two weeks, and the study medication was stopped by the third week during the 3-week duration. | 125 |
| 2: Placebo Arm Description: Matching placebo tablets of dummy strengths of 50 mg and 100 mg were administered orally TID for up to 6 weeks of the Titration Phase, 4 weeks of the Maintenance Phase, and 3 weeks of the Taper Phase. | 62 |
| Total | 187 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Period Title 1: 6-Week Titration Phase | Adverse Event | 18 | 1 |
| Period Title 1: 6-Week Titration Phase | Lack of Efficacy | 5 | 0 |
| Period Title 1: 6-Week Titration Phase | Lost to Follow-up | 2 | 0 |
| Period Title 1: 6-Week Titration Phase | Missed study drug for more than two days | 3 | 1 |
| Period Title 1: 6-Week Titration Phase | Other | 0 | 1 |
| Period Title 1: 6-Week Titration Phase | Physician Decision | 1 | 1 |
| Period Title 1: 6-Week Titration Phase | Protocol Violation | 1 | 0 |
| Period Title 1: 6-Week Titration Phase | Withdrawal by Subject | 6 | 1 |
| Period Title 2: 4-Week Maintenance Phase | Adverse Event | 9 | 1 |
| Period Title 2: 4-Week Maintenance Phase | Lost to Follow-up | 1 | 0 |
| Period Title 2: 4-Week Maintenance Phase | Missed study drug for more than two days | 1 | 1 |
| Period Title 3: 3-Week Taper Phase | Other | 1 | 0 |
Baseline characteristics
| Characteristic | 1: Retigabine | 2: Placebo | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 61 Participants | 28 Participants | 89 Participants |
| Age, Categorical Between 18 and 65 years | 64 Participants | 34 Participants | 98 Participants |
| Age, Continuous | 63.2 years STANDARD_DEVIATION 11.07 | 61.2 years STANDARD_DEVIATION 14.28 | 62.5 years STANDARD_DEVIATION 12.23 |
| Region of Enrollment South Africa | 31 participants | 15 participants | 46 participants |
| Region of Enrollment United States | 94 participants | 47 participants | 141 participants |
| Sex: Female, Male Female | 64 Participants | 36 Participants | 100 Participants |
| Sex: Female, Male Male | 61 Participants | 26 Participants | 87 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 98 / 125 | 29 / 62 |
| serious Total, serious adverse events | 7 / 125 | 1 / 62 |
Outcome results
Primary
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.
Time frame: Baseline and Week 4 (Maintenance Phase-MP)
Population: Per Protocol (PP) Population: all randomized participants who completed the Titration Phase, had at least 1 dose of treatment in the MP, had at least 3 diary entries in the MP, and did not have any protocol violations or any major protocol deviations
| Arm | Measure | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|
| 1: Retigabine | Primary Endpoint Will be the Change From Baseline in Average Pain Score Over the Last 7 Days of the Maintenance Phase. | -2.65 Scores on a scale | Standard Error 0.354 |
| 2: Placebo | Primary Endpoint Will be the Change From Baseline in Average Pain Score Over the Last 7 Days of the Maintenance Phase. | -2.22 Scores on a scale | Standard Error 0.387 |
p-value: 0.253795% CI: [-1.171, 0.312]ANCOVA
Secondary
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.
Time frame: Baseline and Weeks 1, 2, 3, and 4 (MP)
Population: ITT Population. All participants providing data for the measure are included in the analysis. Differences from the overall population numbers are due to missing data or to subjects missing visits.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| 1: Retigabine | Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP) | Category Title 1: Week 1; n=88, 57 | -2.35 Scores on a scale | Standard Deviation 0.323 |
| 1: Retigabine | Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP) | Category Title 3: Week 3; n=78, 56 | -2.82 Scores on a scale | Standard Deviation 0.335 |
| 1: Retigabine | Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP) | Category Title 2: Week 2; n=86, 56 | -2.64 Scores on a scale | Standard Deviation 0.337 |
| 1: Retigabine | Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP) | Category Title 4: Week 4; n=75, 55 | -2.82 Scores on a scale | Standard Deviation 0.32 |
| 2: Placebo | Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP) | Category Title 4: Week 4; n=75, 55 | -2.47 Scores on a scale | Standard Deviation 0.348 |
| 2: Placebo | Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP) | Category Title 1: Week 1; n=88, 57 | -2.08 Scores on a scale | Standard Deviation 0.356 |
| 2: Placebo | Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP) | Category Title 2: Week 2; n=86, 56 | -2.34 Scores on a scale | Standard Deviation 0.372 |
| 2: Placebo | Change From Baseline in Pain Intensity Score at Each Week During the Maintenance Phase (MP) | Category Title 3: Week 3; n=78, 56 | -2.43 Scores on a scale | Standard Deviation 0.363 |
Secondary
Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) SubtypeDeafferentation 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.
Time frame: Baseline and Week 4 Maintenance Phase (MP)
Population: ITT Population. Only participants in the specified subgroup were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1: Retigabine | Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) SubtypeDeafferentation Type 1 (D Type 1) | -3.57 Scores on a scale | Standard Deviation 2.368 |
| 2: Placebo | Change From Baseline in the Average Diary Pain Score to the Last 7 Days of the Maintenance Phase by Post Herpetic Neuralgia (PHN) SubtypeDeafferentation Type 1 (D Type 1) | -5.29 Scores on a scale | Standard Deviation 0 |
Secondary
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.
Time frame: Baseline and Week 4 Maintenance phase (MP)
Population: ITT Population. Only participants in the specified subgroup were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1: Retigabine | 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) | -4.14 Scores on a scale | Standard Deviation 0 |
| 2: Placebo | 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) | 0.00 Scores on a scale | Standard Deviation 0 |
Secondary
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 theirritable 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)
Population: ITT Population. Only participants in the specified subgroup were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1: Retigabine | 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 | -1.78 Scores on a scale | Standard Deviation 2.166 |
| 2: Placebo | 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 | -2.85 Scores on a scale | Standard Deviation 2.163 |
Secondary
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.
Time frame: Baseline and Week 4 Maintenance Phase (MP)
Population: ITT Population. Only participants in the specified subgroup were analyzed.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1: Retigabine | 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 | -2.69 Scores on a scale | Standard Deviation 2.285 |
| 2: Placebo | 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 | -1.87 Scores on a scale | Standard Deviation 1.87 |
Secondary
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.).
Time frame: Baseline and End of Maintenance Phase (MP) (Week 4).
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| 1: Retigabine | 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 | Title 4:Awaken Short of Breath or with a Headache | -4.8 Scores on a scale | Standard Deviation 19.54 |
| 1: Retigabine | 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 | Category Title 1: Overall Sleep Problem Index | -5.70 Scores on a scale | Standard Deviation 15.969 |
| 1: Retigabine | 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 | Category Title 2: Sleep Disturbance | -11.47 Scores on a scale | Standard Deviation 21.802 |
| 1: Retigabine | 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 | Category Title 4: Snoring | 0.7 Scores on a scale | Standard Deviation 23.12 |
| 1: Retigabine | 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 | Category Title 6: Somnolence | 8.10 Scores on a scale | Standard Deviation 20.777 |
| 1: Retigabine | 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 | Category Title 3: Sleep Adequacy | 9.05 Scores on a scale | Standard Deviation 25.536 |
| 2: Placebo | 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 | Category Title 6: Somnolence | -3.39 Scores on a scale | Standard Deviation 18.349 |
| 2: Placebo | 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 | Category Title 2: Sleep Disturbance | -9.43 Scores on a scale | Standard Deviation 22.537 |
| 2: Placebo | 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 | Category Title 3: Sleep Adequacy | 5.26 Scores on a scale | Standard Deviation 26.599 |
| 2: Placebo | 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 | Category Title 4: Snoring | -2.5 Scores on a scale | Standard Deviation 21.07 |
| 2: Placebo | 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 | Title 4:Awaken Short of Breath or with a Headache | -4.6 Scores on a scale | Standard Deviation 22.68 |
| 2: Placebo | 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 | Category Title 1: Overall Sleep Problem Index | -6.88 Scores on a scale | Standard Deviation 16.814 |
Secondary
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.
Time frame: Baseline and End of Maintenance Phase (MP) (Week 4).
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1: Retigabine | 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 | 0.5 Hours | Standard Deviation 1.73 |
| 2: Placebo | 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 | 0.2 Hours | Standard Deviation 1.07 |
Secondary
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).
Time frame: Baseline and Weeks 2 and 4 (Maintenance Phase - MP)
Population: Intent-to-Treat (ITT) Population: all randomized participants who took at least one dose of study medication and had at least one post-randomization efficacy assessment. All participants providing data for the measure are included in the analysis. Differences from the overall population numbers are due to missing data or to subjects missing visits.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| 1: Retigabine | Change From Baseline to Weeks 2 and 4 of the Maintenance Phase in Mean In-clinic Pain Assessment | Category Title 2: Week 4, n=82, 56 | -2.9 Scores on a scale | Standard Deviation 2.41 |
| 1: Retigabine | Change From Baseline to Weeks 2 and 4 of the Maintenance Phase in Mean In-clinic Pain Assessment | Category Title 1:Week 2; n=88, 57 | -2.7 Scores on a scale | Standard Deviation 2.51 |
| 2: Placebo | Change From Baseline to Weeks 2 and 4 of the Maintenance Phase in Mean In-clinic Pain Assessment | Category Title 1:Week 2; n=88, 57 | -2.4 Scores on a scale | Standard Deviation 2.18 |
| 2: Placebo | Change From Baseline to Weeks 2 and 4 of the Maintenance Phase in Mean In-clinic Pain Assessment | Category Title 2: Week 4, n=82, 56 | -2.4 Scores on a scale | Standard Deviation 2.14 |
Secondary
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.
Time frame: End of Maintenance Phase (MP) (Week 4)
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP. Differences from the overall population numbers are due to missing data or to participants missing visits.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| 1: Retigabine | Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase | Category Title 4: Global Satisfaction; n=84, 57 | 58.67 Scores on a scale | Standard Deviation 30.649 |
| 1: Retigabine | Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase | Category Title 1: Effectiveness; n=83, 57 | 59.10 Scores on a scale | Standard Deviation 29.392 |
| 1: Retigabine | Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase | Category Title 2: Side Effects; n=82, 57 | 67.76 Scores on a scale | Standard Deviation 28.097 |
| 1: Retigabine | Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase | Category Title 3: Convenience; n=84, 57 | 69.97 Scores on a scale | Standard Deviation 21.423 |
| 2: Placebo | Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase | Category Title 3: Convenience; n=84, 57 | 74.66 Scores on a scale | Standard Deviation 19.782 |
| 2: Placebo | Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase | Category Title 4: Global Satisfaction; n=84, 57 | 52.88 Scores on a scale | Standard Deviation 34.517 |
| 2: Placebo | Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase | Category Title 2: Side Effects; n=82, 57 | 92.11 Scores on a scale | Standard Deviation 18.28 |
| 2: Placebo | Mean Score on the Treatment Satisfaction Questionnaire for Medication (TSQM) at the End of the Maintenance Phase | Category Title 1: Effectiveness; n=83, 57 | 49.51 Scores on a scale | Standard Deviation 30.143 |
Secondary
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.
Time frame: Baseline and Week 4 Maintenance Phase (MP)
Population: ITT Population. All participants providing data for this analysis had to have 7 available baseline diary entries.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | 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 with >=30% Pain Reduction | 52 Participants |
| 1: Retigabine | 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 with>=50% Pain Reduction | 33 Participants |
| 1: Retigabine | 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 plus NC with>=30% Pain Reduction | 49 Participants |
| 1: Retigabine | 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 plus NC with>=50% Pain Reduction | 33 Participants |
| 2: Placebo | 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 plus NC with>=30% Pain Reduction | 31 Participants |
| 2: Placebo | 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 with >=30% Pain Reduction | 32 Participants |
| 2: Placebo | 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 plus NC with>=50% Pain Reduction | 22 Participants |
| 2: Placebo | 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 with>=50% Pain Reduction | 22 Participants |
Secondary
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?
Time frame: End of Maintenance Phase (MP) (Week 4)
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | 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 | More Sharp | 29 Participants |
| 1: Retigabine | 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 | Less Sharp | 31 Participants |
| 1: Retigabine | 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 | The Same(pain) | 28 Participants |
| 1: Retigabine | 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 | More Painful | 31 Participants |
| 1: Retigabine | 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 | Less Painful | 25 Participants |
| 1: Retigabine | 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 | The Same(sharp) | 24 Participants |
| 2: Placebo | 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 | Less Painful | 15 Participants |
| 2: Placebo | 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 | More Painful | 24 Participants |
| 2: Placebo | 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 | More Sharp | 24 Participants |
| 2: Placebo | 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 | The Same(sharp) | 19 Participants |
| 2: Placebo | 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 | The Same(pain) | 18 Participants |
| 2: Placebo | 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 | Less Sharp | 14 Participants |
Secondary
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.
Time frame: Baseline and End of Maintenance Phase (MP) (Week 4).
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | 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 | Category Title 1: Improved | 12 Participants |
| 1: Retigabine | 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 | Category Title 2: Same | 63 Participants |
| 1: Retigabine | 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 | Category Title 3: Worse | 9 Participants |
| 2: Placebo | 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 | Category Title 1: Improved | 8 Participants |
| 2: Placebo | 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 | Category Title 2: Same | 42 Participants |
| 2: Placebo | 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 | Category Title 3: Worse | 7 Participants |
Secondary
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.
Time frame: Baseline to the end of Maintenance Phase (MP) (Week 4)
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 3: Minimally Improved | 19 Participants |
| 1: Retigabine | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 5: Minimally Worse | 3 Participants |
| 1: Retigabine | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 2: Much Improved | 27 Participants |
| 1: Retigabine | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 6: Much Worse | 1 Participants |
| 1: Retigabine | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 4: No Change | 14 Participants |
| 1: Retigabine | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 7: Very Much Worse | 0 Participants |
| 1: Retigabine | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 1: Very Much Improved | 20 Participants |
| 2: Placebo | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 7: Very Much Worse | 0 Participants |
| 2: Placebo | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 1: Very Much Improved | 8 Participants |
| 2: Placebo | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 2: Much Improved | 15 Participants |
| 2: Placebo | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 3: Minimally Improved | 10 Participants |
| 2: Placebo | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 4: No Change | 21 Participants |
| 2: Placebo | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 5: Minimally Worse | 2 Participants |
| 2: Placebo | Number of Participants With the Indicated Overall Patient Global Impression of Change (PGIC) | Category Title 6: Much Worse | 1 Participants |
Secondary
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?.
Time frame: Baseline Phase (Day -7 to Randomization Day 0)
Population: ITT Population - All participants providing data for the measure are included in the analysis. Differences from the overall population numbers are due to missing data or to subjects missing visits.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | 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 | Category Title 1: More Painful | 89 Participants |
| 1: Retigabine | 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 | Category Title 3: Less Painful | 16 Participants |
| 1: Retigabine | 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 | Category Title 2: The Same | 19 Participants |
| 2: Placebo | 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 | Category Title 1: More Painful | 40 Participants |
| 2: Placebo | 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 | Category Title 3: Less Painful | 7 Participants |
| 2: Placebo | 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 | Category Title 2: The Same | 14 Participants |
Secondary
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?
Time frame: Timeframe: Baseline Phase (Day -7 to Randomization Day 0)
Population: ITT Population - All participants providing data for the measure are included in the analysis. Differences from the overall population numbers are due to missing data or to subjects missing visits.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | 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 | Is Not Cool | 19 Participants |
| 1: Retigabine | 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 | Is Cool | 105 Participants |
| 1: Retigabine | 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 | Is Not Painful | 67 Participants |
| 1: Retigabine | 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 | Is Painful | 57 Participants |
| 2: Placebo | 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 | Is Painful | 27 Participants |
| 2: Placebo | 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 | Is Not Cool | 9 Participants |
| 2: Placebo | 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 | Is Not Painful | 34 Participants |
| 2: Placebo | 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 | Is Cool | 52 Participants |
Secondary
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.
Time frame: End of Maintenance Phase (MP) (Week 4)
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | 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 | More Painful | 30 Participants |
| 1: Retigabine | 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 | The Same | 44 Participants |
| 1: Retigabine | 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 | Less Painful | 10 Participants |
| 2: Placebo | 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 | More Painful | 29 Participants |
| 2: Placebo | 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 | The Same | 20 Participants |
| 2: Placebo | 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 | Less Painful | 8 Participants |
Secondary
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?
Time frame: End of Maintenance Phase (MP) (Week 4)
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | 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 | Is Not Painful | 63 Participants |
| 1: Retigabine | 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 | Is Cool | 70 Participants |
| 1: Retigabine | 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 | Is Painful | 21 Participants |
| 1: Retigabine | 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 | Is Not Cool | 14 Participants |
| 2: Placebo | 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 | Is Painful | 13 Participants |
| 2: Placebo | 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 | Is Cool | 50 Participants |
| 2: Placebo | 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 | Is Not Painful | 44 Participants |
| 2: Placebo | 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 | Is Not Cool | 7 Participants |
Secondary
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.
Time frame: Weeks 1, 2, 3, and 4 Maintenance Phase
Population: ITT Population. All participants providing data for the measure are included in the analysis. Differences from the overall population numbers are due to missing data or to subjects missing visits.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| 1: Retigabine | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 1: Week 1; n=88, 57 | 0.92 Tablets/Day | Standard Deviation 1.357 |
| 1: Retigabine | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 4: Week 4; n=76, 55 | 0.83 Tablets/Day | Standard Deviation 1.34 |
| 1: Retigabine | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 2: Week 2; n=86, 56 | 0.89 Tablets/Day | Standard Deviation 1.228 |
| 1: Retigabine | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 3: Week 3; n=82, 56 | 0.74 Tablets/Day | Standard Deviation 1.174 |
| 1: Retigabine | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 5: All Maintenance Phase Weeks; n=8 | 0.87 Tablets/Day | Standard Deviation 1.211 |
| 2: Placebo | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 5: All Maintenance Phase Weeks; n=8 | 0.83 Tablets/Day | Standard Deviation 1.193 |
| 2: Placebo | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 3: Week 3; n=82, 56 | 0.85 Tablets/Day | Standard Deviation 1.254 |
| 2: Placebo | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 1: Week 1; n=88, 57 | 0.84 Tablets/Day | Standard Deviation 1.239 |
| 2: Placebo | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 4: Week 4; n=76, 55 | 0.77 Tablets/Day | Standard Deviation 1.218 |
| 2: Placebo | Number of Rescue Medication Tablets Taken Per Day During the Maintenance Phase (MP) | Category Title 2: Week 2; n=86, 56 | 0.79 Tablets/Day | Standard Deviation 1.158 |
Secondary
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?
Time frame: Baseline Phase (Day -7 to Randomization Day 0)
Population: ITT Population - All participants providing data for the measure are included in the analysis. Differences from the overall population numbers are due to missing data or to subjects missing visits.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1: Retigabine | 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 | Less Painful | 34 Participants |
| 1: Retigabine | 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 | The Same(sharp) | 7 Participants |
| 1: Retigabine | 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 | The Same(pain) | 19 Participants |
| 1: Retigabine | 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 | Less sharp | 51 Participants |
| 1: Retigabine | 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 | More Sharp | 66 Participants |
| 1: Retigabine | 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 | More Painful | 71 Participants |
| 2: Placebo | 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 | More Sharp | 32 Participants |
| 2: Placebo | 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 | The Same(pain) | 7 Participants |
| 2: Placebo | 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 | Less Painful | 16 Participants |
| 2: Placebo | 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 | More Painful | 38 Participants |
| 2: Placebo | 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 | The Same(sharp) | 10 Participants |
| 2: Placebo | 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 | Less sharp | 19 Participants |
Secondary
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.
Time frame: End of maintenance Phase (MP) (Week 4)
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP. Differences from the overall population numbers are due to missing data or to participants missing visits.
| Arm | Measure | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|
| 1: Retigabine | 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 | 2.68 Scores on a scale | Standard Error 0.102 |
| 2: Placebo | 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 | 2.37 Scores on a scale | Standard Error 0.125 |
Secondary
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%
Time frame: End of Maintenance Phase (MP) (Week 4)
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP. Differences from the overall population numbers are due to missing data or to participants missing visits.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| 1: Retigabine | 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 | Category Title 1: Pain Intensity; n=74, 49 | 3.17 Scores on a scale | Standard Deviation 2.092 |
| 1: Retigabine | 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 | Category Title 2: Pain Interference; n=75, 49 | 2.00 Scores on a scale | Standard Deviation 2.159 |
| 1: Retigabine | 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 | Category Title 3: Pain Relief; n=74, 48 | 58.4 Scores on a scale | Standard Deviation 35.04 |
| 2: Placebo | 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 | Category Title 2: Pain Interference; n=75, 49 | 2.27 Scores on a scale | Standard Deviation 2.147 |
| 2: Placebo | 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 | Category Title 1: Pain Intensity; n=74, 49 | 3.58 Scores on a scale | Standard Deviation 2.299 |
| 2: Placebo | 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 | Category Title 3: Pain Relief; n=74, 48 | 49.4 Scores on a scale | Standard Deviation 36.17 |
Secondary
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.
Time frame: End of Maintenance Phase (MP) (Week 4)
Population: ITT Population includes all participants who entered MP and provided data. End of Maintenance Phase includes participants who completed Week 4 of the MP and who terminated early during the MP. Differences from the overall population numbers are due to missing data or to participants missing visits.
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| 1: Retigabine | 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 | Category Title10: Mental Component Summary; n=83, | 51.22 Scores on a scale | Standard Error 0.944 |
| 1: Retigabine | 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 | Category Title 1: General health; n=83, 55 | 51.12 Scores on a scale | Standard Error 0.816 |
| 1: Retigabine | 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 | Category Title3: Role limitations, physical; n=84, | 43.22 Scores on a scale | Standard Error 1.046 |
| 1: Retigabine | 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 | tegory Title 5: Social Functioning; n=84, 55 | 50.14 Scores on a scale | Standard Error 0.858 |
| 1: Retigabine | 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 | Category Title4: Role limitations, emotional; n=84 | 44.31 Scores on a scale | Standard Error 1.226 |
| 1: Retigabine | 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 | Category Title 8: Mental Health; n=84, 55 | 51.66 Scores on a scale | Standard Error 0.871 |
| 1: Retigabine | 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 | Category Title 2: Physical Functioning; n=84, 55 | 43.82 Scores on a scale | Standard Error 0.87 |
| 1: Retigabine | 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 | Category Title 7: Vitality; n=84, 55 | 51.68 Scores on a scale | Standard Error 0.904 |
| 1: Retigabine | 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 | Category Title9: Physical Component Summary; n=83, | 45.26 Scores on a scale | Standard Error 0.691 |
| 1: Retigabine | 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 | Category Title 6: Bodily Pain; n=84, 55 | 47.23 Scores on a scale | Standard Error 0.883 |
| 2: Placebo | 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 | Category Title10: Mental Component Summary; n=83, | 50.91 Scores on a scale | Standard Error 1.16 |
| 2: Placebo | 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 | Category Title 2: Physical Functioning; n=84, 55 | 45.54 Scores on a scale | Standard Error 1.076 |
| 2: Placebo | 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 | tegory Title 5: Social Functioning; n=84, 55 | 50.25 Scores on a scale | Standard Error 1.061 |
| 2: Placebo | 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 | Category Title 7: Vitality; n=84, 55 | 53.94 Scores on a scale | Standard Error 1.117 |
| 2: Placebo | 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 | Category Title 8: Mental Health; n=84, 55 | 51.34 Scores on a scale | Standard Error 1.076 |
| 2: Placebo | 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 | Category Title9: Physical Component Summary; n=83, | 45.65 Scores on a scale | Standard Error 0.849 |
| 2: Placebo | 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 | Category Title3: Role limitations, physical; n=84, | 43.30 Scores on a scale | Standard Error 1.293 |
| 2: Placebo | 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 | Category Title4: Role limitations, emotional; n=84 | 42.68 Scores on a scale | Standard Error 1.517 |
| 2: Placebo | 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 | Category Title 6: Bodily Pain; n=84, 55 | 45.60 Scores on a scale | Standard Error 1.091 |
| 2: Placebo | 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 | Category Title 1: General health; n=83, 55 | 50.47 Scores on a scale | Standard Error 1.002 |