Trial Outcomes & Findings for Long-Term Study of Gabapentin Enacarbil (GEn, XP13512) vs. Placebo in Patients With Restless Legs Syndrome. (NCT NCT00311363)

There were 27 participants who completed the Single-blind Treatment Period who either elected not to enroll into the Double-blind Treatment Period or were considered non-responders and were not randomized.

Long-Term Study of Gabapentin Enacarbil (GEn, XP13512) vs. Placebo in Patients With Restless Legs Syndrome.

Relapse was defined as worsening of Restless Legs Syndrome (RLS) symptoms or withdrawal due to lack of efficacy during the 12-week double-blind (DB) treatment period (the period from Randomization on Visit 14 \[Week 24\] through the end of treatment). Worsening of symptoms was defined as an increase in the total International RLS (IRLS) Scale score by at least 6 or more points relative to the participant's score at Randomization, achieving an IRLS score of at least 15, and an assessment of "much worse" or "very much worse" on the investigator-rated Clinical Global Impression of Change (CGI-C).

Time to relapse was defined as the time until worsening of Restless Legs Syndrome (RLS) symptoms or withdrawal due to lack of efficacy during the 12-week Double-blind (DB) treatment period (same as primary outcome definition). Note: The median is not estimable with Kaplan-Meier methodology when fewer than 50% of participants experience an event. The median is not estimable for this outcome.

Time to relapse was defined as the time until worsening of Restless Legs Syndrome (RLS) symptoms or withdrawal due to lack of efficacy during the 12-week Double-blind (DB) treatment period (same as primary outcome definition). Note: The median is not estimable with Kaplan-Meier methodology when fewer than 50% of participants experience an event. The median is not estimable for this outcome.

The IRLS Rating scale is a measure of RLS disease severity and reflects the participant-reported assessment of primary sensory and motor features and associated sleep problems in RLS. Items are included that assess the impact of symptoms on participants' mood, daily life, and activities. The total score ranges from 0-40 points, with 40 being the most severe. The scale assesses symptoms over the week prior to measurement. LOCF: Missing data (MD) values were imputed using the last non-missing observation prior to the visit with MD; randomization visit data could be carried forward.

The CGI-C scale is a widely used tool designed to allow clinicians to rate the severity of illness and the change over time based on a seven-point rating scale, with a score of 1 being "very much improved" and a score of 7 being "very much worse" compared to baseline. For this endpoint, "response" on the CGI-C was defined as participants with a rating of "no change," (score of 4) "minimally improved," (score of 3) "much improved," (score of 2) or "very much improved" (score of 1) compared to Randomization (Week 24).

The CGI scale is a widely used tool designed to allow clinicians to rate the severity of illness and the change over time based on a seven-point rating scale, with a score of 1 being "very much improved" and a score of 7 being "very much worse" compared to baseline.

The participant-rated CGI-I scale is a self-rated assessment designed to allow participants to rate the change of their disease severity over time based on a seven-point scale, with a score of 1 being "very much improved" and a score of 7 being "very much worse" compared to baseline.

The participant-rated CGI-I scale is a self-rated assessment designed to allow participants to rate the change of their disease severity over time based on a seven-point scale, with a score of 1 being "very much improved," and a score of 7 being "very much worse." Response on the participant-rated CGI-I was defined as a rating of "very much improved" (score of 1) or "much improved" (score of 2) compared to Baseline of the SB phase.

The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. Responses are recoded so that a higher score reflects more of the attribute, and then converted to a 0 to 100 scale. The daytime somnolence score is based on questions pertaining to feeling drowsy or sleepy, trouble staying awake, and taking naps \> 5 minutes. For daytime somnolence, a negative value indicates an improvement.

The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. The MOS Sleep Scale sleep disturbance domain is a participant-rated measure of sleep disturbance over the month prior to the measurement. Questions are scored, and responses are converted to a 0 to 100 scale, with lower scores representing less sleep disturbance.

The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. The MOS Sleep Scale sleep adequacy domain is a participant-rated measure of the adequacy of sleep over the month prior to measurement. Questions are scored, and responses are converted to a 0 to 100 scale, with higher scores representing more adequate ratings of sleep.

The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. The Sleep Quantity Domain score is a participant-rated estimate of the average number of hours of sleep per night over the month.

The RLS QoL is an 18-item scale assessing the impact of RLS on daily life, emotional well-being, social and work life. Responses range from 1 (not at all/never) to 5 (a lot/all of the time). Ten items contribute to a single summary score, the Overall Life Impact, which is standardized to range from 0-100, with lower scores representing better QoL.

In the 24-hour RLS Record (diary), participants report the presence and severity of RLS symptoms (none, mild, moderate, or severe) for a 24-hour period, in 30-minute increments. The period was divided into 7 four-hr intervals (8 AM to 12 PM, 12 to 4 PM, 4 to 8 PM, 6 to 10 PM, 8 to Midnight, Midnight to 4 AM, 4 to 8 AM)

The 24-hour RLS Record is a diary in which participants report the presence and severity of RLS symptoms (none, mild, moderate, or severe) for a 24-hour period, in 30-min increments beginning at 8AM on the day prior to the visit. Note: The median is not estimable with Kaplan-Meier methodology when fewer than 50% of participants experience an event; thus, no data are presented for the DB GEn 1200 mg arm.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The IRLS Rating scale is a measure of disease severity. The scale reflects participant-reported assessment of sensory and motor features and associated sleep problems in RLS. In addition, items are included that assess the impact of symptoms on participants' mood, daily life, and activities. Total score ranges from 0-40 points, with 40 being the most severe.

The CGI-I scale is a widely used tool designed to allow clinicians to rate the severity of illness and the change over time based on a seven-point rating scale, with a score of 1 being "very much improved" and a score of 7 being "very much worse" compared to baseline.

The participant-rated CGI-I scale is a self-rated assessment designed to allow participants to rate the change of their disease severity over time based on a seven-point rating scale, with a score of 1 being "very much improved" and a score of 7 being "very much worse" compared to baseline.

The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. Responses are recoded so that a higher score reflects more of the attribute, and then converted to a 0 to 100 scale. The daytime somnolence score is based on questions pertaining to feeling drowsy or sleepy, trouble staying awake, and taking naps \> 5 minutes. For daytime somnolence, a negative value indicates an improvement.

The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. . The MOS Sleep Scale sleep disturbance domain is a participant-rated measure of sleep disturbance over the month prior to the measurement. Questions are scored, and responses are converted to a 0 to 100 scale, with lower scores representing less sleep disturbance.

The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and daytime somnolence. The MOS Sleep Scale sleep adequacy domain is a participant-rated measure of the adequacy of sleep over the month prior to measurement. Questions are scored, and responses are converted to a 0 to 100 scale, with higher scores representing more adequate ratings of sleep.

The MOS Sleep Scale is a participant-rated non-disease-specific measure with questions relating to four areas related to sleep: quantity (number of hours slept), sleep disturbance, sleep adequacy, and somnolence. The Sleep Quantity Domain score is a participant-rated estimate of the average number of hours of sleep per night over the month.

The RLS QoL is an 18-item scale assessing the impact of RLS on daily life, emotional well-being, social and work life. Responses range from 1 (not at all/never) to 5 (a lot/all of the time). Ten items contribute to a single summary score, the Overall Life Impact, which is standardized to range from 0-100, with lower scores representing better QoL.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.

The PSQ is designed to evaluate sleep quality, ability to function, and the degree to which RLS symptoms interfere with sleep. Participants rated overall sleep quality and their ability to function on scales ranging from "excellent" to "poor" and were asked to provide the number of nights they experienced RLS symptoms and the number of times/hours they awoke at night during the week prior to the measurement.