Sativex Versus Placebo When Added to Existing Treatment for Central Neuropathic Pain in MS

• Change in Mean Pain Due to MS NRS Score [ Time Frame: 14 weeks: Baseline - End of Treatment (last 7 days of treatment) ] [ Designated as safety issue: No ]
  The pain NRS was completed at the same time each day, i.e. bedtime in the evening. The patient was asked "on a scale of '0 to 10', please indicate the number that best describes your pain in the last 24 hours" where 0 = no pain and 10 = pain as bad as you can imagine. No pain relates to the time prior to the onset of pain due to multiple sclerosis. A negative value indicates an improvement in pain score from baseline.
  
  
• Number of Patients With at Least 30% Improvement in Numerical Rating Scale (NRS) Pain Score From Baseline [ Time Frame: 14 weeks: Baseline - end of treatment (last 7 days) ] [ Designated as safety issue: No ]
  A positive 30% pain response is defined as a reduction of at least 30% in the mean NRS pain score from baseline to week 14 (last 7 days). The patient was asked "on a scale of '0 to 10', please indicate the number that best describes your pain in the last 24 hours" where 0 = no pain and 10 = pain as bad as you can imagine. No pain relates to the time prior to the onset of pain due to multiple sclerosis. The pain NRS was completed at the same time each day, i.e. bedtime in the evening.
  
  

• Change in Pain From Baseline to End of the Treatment Using the NPS (Neuropathic Pain Scale) [ Time Frame: 14 weeks: Baseline - End of treatment (Week 14) ] [ Designated as safety issue: No ]
  The NPS score is 0-100 sum of 10 individual pain scores (0-10 NRS, 0= no pain to 10 = most pain imaginable). A negative change from baseline indicates an improvement in pain.
  
  
• Change From Baseline to End of Treatment in Break-through Analgesia Usage [ Time Frame: 14 weeks: baseline - end of treatment (last 7 days) ] [ Designated as safety issue: No ]
  Use of break through medication was recorded daily during the 14 weeks of the study as the number of paracetamol tablets taken. The change in mean daily quantities of tablets used was calculated from baseline to the last seven days of treatment.
  
  
• Change From Baseline to End of Treatment in BPI (Brief Pain Inventory) Short Form [ Time Frame: 14 weeks: Baseline to end of treatment (last 7 days of treatment) ] [ Designated as safety issue: No ]
  The BPI-SF is a 14-item questionnaire that asks patients to rate pain over the prior week and the degree to which it interferes with activities on a 0 to 10 scale, where 0=no pain and 10=pain as bad as you can imagine. Severity is measured as worst pain, least pain, average pain, and pain right now. The severity composite score was calculated as the arithmetic mean of the four severity items(range 0-10). The minimum value is zero and maximum is 10. A higher score represents a poor outcome.
  
  
• Change in Subject Global Impression of Change (SGIC) [ Time Frame: Week 14 ] [ Designated as safety issue: No ]
  A 7-point Likert-type scale was used, with the question: 'Please assess the status of your pain due to multiple sclerosis since entry into the study using the scale below' with the markers "very much improved, much improved, slightly improved, no change, slightly worse, much worse or very much worse". At baseline subjects wrote a brief description of their pain caused by multiple sclerosis which was used at Week 14 to aid their memory regarding their symptoms at study start. For each of above markers the number of participants were reported.
  
  
• Change in Sleep Disruption NRS [ Time Frame: 14 weeks; Baseline to end of treatment (last 7 days) ] [ Designated as safety issue: No ]
  The sleep disruption NRS was completed at the same time each day, i.e. bedtime in the evening. The patient was asked "on a scale of '0 to 10', please indicate how your pain disrupted your sleep last night?" where 0 = did not disrupt sleep and 10 = completely disrupted (unable to sleep at all). A negative value indicates an improvement in sleep disruption score from baseline.
  
  

GW has shown in phase II and III studies that Sativex has analgesic properties that are effective in relieving neuropathic pain. These studies suggested that Sativex is well tolerated and may also improve sleep and quality of life. GW is conducting this study to further demonstrate these effects.