Study of Retigabine Immediate Release as Adjunctive Therapy to Specified Monotherapy Antiepileptic Treatments in Adults With Partial-Onset Seizures

The number of participants experiencing a >=50% reduction from Baseline (BL) in POS frequency during the Treatment Phase (TP) (i.e., Titration Phase and Flexible Dose Evaluation [FDE] Phase) was measured. A POS has its onset in a limited area on one side of the brain. POSs may remain limited or may spread to involve both sides of the brain. For both the Baseline Phase and the TP, seizure frequency was calculated as a 28-day rate using the following formula: 28 x {[(number of countable partial seizures in Phase) + (10 x number of days with innumerable seizures in Phase) + (number of occurrences of status epilepticus in Phase)] / number of applicable days in the Phase}, where all days in the Phase are considered applicable (including days with 0 seizures), except for days on which the participant failed to complete the Seizure Diary. >= 50% reduction from BL is calculated as 100 x (28-day partial seizure rate [PSR] for the TP - 28-day PSR for the BL Phase) / 28-day PSR for the BL Phase.

Participants were assessed for the percent change from Baseline in seizure frequency; changes were categorized as Any Decrease (>0 to 25%, 25 to <50%, 50 to 75%, >75 to 100%) or No Change or Any Increase (>25%, 0 to 25%). A partial-onset seizure is a seizure that has its onset in a limited area on one side of the brain. Partial-onset seizures may remain limited or may spread to involve both sides of the brain.

The number of participants experiencing a >=25%, >=75%, and 100% reduction from Baseline in partial-onset seizure frequency during the Treatment Phase (TP) (i.e., Titration Phase and Flexible Dose Evaluation [FDE] Phase) was measured. A partial-onset seizure is a seizure that has its onset in a limited area on one side of the brain. Partial-onset seizures may remain limited or may spread to involve both sides of the brain.

Percent change from Baseline was calculated as the difference in the partial-onset seizure frequency (Treatment Phase minus the Baseline Phase) divided by the Baseline Phase frequency, multiplied by 100. Negative values indicate reductions from Baseline. A partial-onset seizure is a seizure that has its onset in a limited area on one side of the brain. Partial-onset seizures may remain limited or may spread to involve both sides of the brain.

Participants were asked the following question daily: "How would you rate your epilepsy-related worry over the last 24 hours?" The original possible responses were 0-10, with 0="No worry" and 10="Worst worry imaginable." However, in the summarization, "1" was added to each participant's daily response, changing the possible values to 1-11, so that there would be no possibility of the percent change from Baseline being undefined. Baseline and Treatment Phase averages were calculated for each participant. The denominators for these by-phase averages were the number of non-missing days for each variable and phase. The by-phase averages were used as follows in the calculation of percent change from Baseline for each participant: 100 x Treatment Phase average - Baseline Phase average) / Baseline Phase average. A negative percent change from Baseline indicates a reduction from Baseline.

Participants were asked the following question daily: "How would you rate the extent to which epilepsy limited your ability to do what you needed to do over the last 24 hours?" The original possible responses were 0-10, with 0="Not at all limited" and 10="Unable to do anything I needed to." However, in the summarization, "1" was added to each participant's daily response, changing the possible values to 1-11, so that there would be no possibility of the percent change from Baseline being undefined. Baseline and Treatment Phase averages were calculated for each participant. The denominators for these by-phase averages were the number of non-missing days for each variable and phase. The by-phase averages were used as follows in the calculation of percent change from Baseline for each participant: 100 x Treatment Phase average - Baseline Phase average) / Baseline Phase average. A negative percent change from Baseline indicates a reduction from Baseline.

Participants were asked the following question daily: "How would you rate the extent to which epilepsy limited your ability to do what you wanted to do over the last 24 hours?" The original possible responses were 0-10, with 0="Not at all limited" and 10="Unable to do anything I wanted to." However, in the summarization, "1" was added to each participant's daily response, changing the possible values to 1-11, so that there would be no possibility of the percent change from Baseline being undefined. Baseline and Treatment Phase averages were calculated for each participant. The denominators for these by-phase averages were the number of non-missing days for each variable and phase. The by-phase averages were used as follows in the calculation of percent change from Baseline for each participant: 100 x Treatment Phase average - Baseline Phase average) / Baseline Phase average. A negative percent change from Baseline indicates a reduction from Baseline.

Participants were asked the following question daily: "Did you miss any time from work or school in the last 24 hours due to epilepsy?" Possible responses were Yes, No, and NA=Not Applicable (no planned work or school in the last 24 hours). The variable summarized is the percentage of days with no missed work or school. Baseline and Treatment Phase averages were calculated for each participant. The denominators for these by-phase averages were the number of non-missing days for each variable and phase. The by-phase averages were used as follows in the calculation of percent change from Baseline for each participant: 100 x Treatment Phase average - Baseline Phase average) / Baseline Phase average. A positive percent change from Baseline indicates a reduction from Baseline in missed work or school.

The SF-36v2 health survey is a self-administered, generic, 36-item questionnaire designed to measure 8 domains of functional health status and well-being: physical functioning, role-physical, bodily pain, general health perceptions, vitality, social functioning, role-emotional, and mental health. Each domain is scored from 0 (poorer health) to 100 (better health). Change from Baseline was calculated as the post-Baseline score minus the Baseline score. Positive changes from Baseline indicate improvement.

The SF-36 v2 Health Survey is a self-administered, generic, 36-item questionnaire designed to measure 8 domains of functional health status and well-being: physical functioning, role-physical, bodily pain, general health perceptions, vitality, social functioning, role-emotional, and mental health. Each domain is scored from 0 (poorer health) to 100 (better health).The physical component summary (PCS) score is a summary score representing overall physical health, which is derived from the 8 domains. As with the domains, PCS scores range from 0 to 100; higher scores represent better health. Change from Baseline was calculated as the post-Baseline score minus the Baseline score. Positive changes from Baseline indicate improvement.

The SF-36 v2 Health Survey is a self-administered, generic, 36-item questionnaire designed to measure 8 domains of functional health status and well-being: physical functioning, role-physical, bodily pain, general health perceptions, vitality, social functioning, role-emotional, and mental health. Each domain is scored from 0 (poorer health) to 100 (better health).The mental component summary (MCS) score is a summary score representing overall mental health, which is derived from the 8 domains. As with the domains, MCS scores range from 0 to 100; higher scores represent better health. Change from Baseline was calculated as the post-Baseline score minus the Baseline score. Positive changes from Baseline indicate improvement.

The PGI-C questionnaire was to be completed by the participant. Participants were asked the following question: Compared to before you started this study, how would you rate your current epilepsy-related worry: Much better, Moderately better, A little better, Unchanged, A little worse, Moderately worse, Much worse?

The PGI-C questionnaire was to be completed by the participant. Participants were asked the following question: Compared to before you started this study, how would you rate your current epilepsy-related worry: Much better, Moderately better, A little better, Unchanged, A little worse, Moderately worse, Much worse? Rating scores are integers from 1 to 7, with 1=Much better and 7=Much worse.

The PGI-C questionnaire was to be completed by the participant. Participants were asked the following question: Compared to before you started this study, how would you rate your current ability to do the things you need to do: Much better, Moderately better, A little better, Unchanged, A little worse, Moderately worse, Much worse?

The PGI-C questionnaire was to be completed by the participant. Participants were asked the following question: Compared to before you started this study, how would you rate your current ability to do the things you need to do: Much better, Moderately better, A little better, Unchanged, A little worse, Moderately worse, Much worse? Rating scores are integers from 1 to 7, with 1=Much better and 7=Much worse.

The PGI-C questionnaire was to be completed by the participant. Participants were asked the following question: Compared to before you started this study, how would you rate your current ability to do the things you want to do: Much better, Moderately better, A little better, Unchanged, A little worse, Moderately worse, Much worse.

The PGI-C questionnaire was to be completed by the participant. Participants were asked the following question: Compared to before you started this study, how would you rate your current ability to do the things you want to do: Much better, Moderately better, A little better, Unchanged, A little worse, Moderately worse, Much worse? Rating scores are integers from 1 to 7, with 1=Much better and 7=Much worse.