• Percent Change From Baseline in 28 Day Partial Seizure Rate During Treatment Observation Phase [ Time Frame: Week 9 to Week 21 or End of Treatment (early termination) ] [ Designated as safety issue: Yes ]
  28-day seizure rate (at observation period [obs]) = [(number of seizures obs ) divided by (duration of period based on observed last dosing date and Visit 3 [Week 9] date)] * 28. Percent change = [(28-day seizure rate obs minus 28-day seizure rate at baseline [b]) divided by 28-day seizure rate b] * 100. Negative values indicate a decrease in seizure frequency and positive values reflect an increase in seizure frequency.
  
  

• Response Ratio (RR) [ Time Frame: Week 9 to Week 21 or End of Treatment (early termination) ] [ Designated as safety issue: No ]
  Response ratio (RR) = comparison between baseline 28-seizure frequency with the 12 week observation phase. RR = [(28-day seizure rate in observation period [obs] minus 28-day seizure rate at baseline [b] ) divided by (28-day seizure rate obs plus 28-day seizure rate b)] * 100. Range: -100 to 100; negative values for the RR indicate reductions in seizures.
  
  
• Percent Change From Baseline in 28-Day Partial Seizure Frequency at Week 21 [ Time Frame: Week 21 or End of Treatment (early termination) ] [ Designated as safety issue: No ]
  Percent change from Baseline = [(28-day seizure rate at 21 weeks minus 28-day seizure rate at baseline [b]) divided by (28-day seizure rate b) * 100. Negative values indicate a decrease in seizure frequency, positive values reflect an increase in seizure frequency.
  
  
• Percent Change From Baseline in Seizure Frequency in Participants Who Had <=6 Seizures and >6 Seizures During the Baseline Period [ Time Frame: Week 9 to Week 21 or End of Treatment (early termination) ] [ Designated as safety issue: Yes ]
  Negative values indicate a decrease in seizure frequency; positive values reflect an increase in seizure frequency.
  
  
• Percent of Seizure- Free Participants During the Treatment Observation Period [ Time Frame: Week 9 to Week 21 or Early Termination (end of treatment) ] [ Designated as safety issue: Yes ]
  Seizure-free = no seizures during observation period (100 percent reduction in seizures from baseline).
  
  
• Percent of Seizure Free Participants During the Last 4 Weeks of the Treatment Observation Period [ Time Frame: Week 17 to Week 21 (or Last 4 Weeks of Treatment after Week 9) ] [ Designated as safety issue: Yes ]
  Seizure-free = no seizures during last 4 weeks of observation period (100 percent reduction in seizures from baseline).
  
  
• Percent of Participants With >=50% Reduction in Seizure Frequency (28-day Seizure Rate) Between Baseline and Final 4 Weeks of the Treatment Observation Period [ Time Frame: Week 17 to Week 21 (or Last 4 Weeks of Treatment after Week 9) ] [ Designated as safety issue: Yes ]
  
• Percent of Participants With >=75% Reduction in Seizure Frequency (28-day Seizure Rate) Between Baseline and Final 4 Weeks of the Treatment Observation Period [ Time Frame: Week 17 through Week 21 (or Last 4 Weeks of Treatment after Week 9) ] [ Designated as safety issue: Yes ]
  
• Treatment Satisfaction: Patient General Impression to Change (PGIC) [ Time Frame: Week 21, LOCF ] [ Designated as safety issue: Yes ]
  Patient General Impression to Change (PGIC): participant rated instrument to measure participant's change in overall status since beginning study medication on a 7-point scale; range: 1 (very much improved) to 7 (very much worse). Not done = participant did not complete the PGIC.
  
  
• Change From Baseline in Sleep Interference: Medical Outcome Sleep Scale (MOS) [ Time Frame: Week 21, LOCF ] [ Designated as safety issue: No ]
  Participant rated questionnaire to assess sleep quality and quantity; 9-item overall sleep problems index and 7 subscales. Sleep disturbance, snoring, awaken short of breath, somnolence, and adequacy subscale scores (s) rated 1 (all the time) to 6 (none of the time); transformed s; total range (r): 0 to 100; higher s = greater intensity of attribute; negative values (v) = reduction from baseline (b), positive v = increase from b. Sleep Quantity score r: 0-24 hours. Higher s = greater quantity of sleep. Change = (MOS score at observation period minus MOS score at b) divided by MOS score b.
  
  
• Change From Baseline in Sleep Interference: Medical Outcome Sleep Scale (MOS): Optimal Sleep Subscale [ Time Frame: Week 21, LOCF ] [ Designated as safety issue: No ]
  Optimal Sleep subscale of the MOS subject rated questionnaire to assess sleep quality and quantity. Optimal Sleep (1 of 7 subscales) was derived from sleep quantity: average hours of sleep each night during the past week. Number of subjects with response: YES=1 (optimal sleep: quantity of sleep was 7 or 8 hours per night) or No= 0 (no optimal sleep). Negative value indicates a decrease in attribute; positive value indicates an increase in attribute. Change = (MOS score at observation period minus MOS score at baseline [b]) divided by MOS score b.
  
  
• Change From Baseline in Hospital Anxiety and Depression Scale (HADS) [ Time Frame: Week 21, LOCF ] [ Designated as safety issue: Yes ]
  Participant rated questionnaire with 2 subscales: HADS-A assesses generalized anxiety (anxious mood, restlessness, anxious thoughts, panic attacks); HADS-D: state of lost interest and diminished pleasure response (lowering of hedonic tone). Each subscale has 7 items; range: 0 (no anxiety or depression) to 3 (severe anxiety or depression). Total score 0 to 21 for each subscale; higher score = greater severity of symptoms. Negative value = reduction from baseline (b), positive value = increase from b. Change = (HADS score at observation period minus HADS score at b) divided by HADS score b.
  
  

This study was terminated on 17 March 2009 due to delayed enrollment. The decision to terminate the trial was not based on any safety concerns, but rather on timelines and the difficulty in enrolling patients in this open label, single group study.