Trial Outcomes & Findings for Study Evaluating LAMICTAL Extended-Release Therapy Added To Current Seizure Treatments In Patients With Primary Generalized Tonic-Clonic Seizures (PGTC) Seizures (NCT NCT00104416)

All participants (par.) that complete the Treatment Phase (TP) and all Baseline Failures (par. who did not meet randomization seizure criteria necessary to qualify for the TP) are eligible to enter the Continuation Phase (CP). The CP is for long-term safety exposure to lamotrigine (LTG) extended release (XR); it is not a cross-over phase.

The number of par. starting the CP does not equal the number completing the TP, as 1) the CP was optional, 2) not everyone from the TP was eligible to enter the CP, and 3) Baseline Failures were allowed to enter the CP, however they were not included in the "started" count for the TP.

Study Evaluating LAMICTAL Extended-Release Therapy Added To Current Seizure Treatments In Patients With Primary Generalized Tonic-Clonic Seizures (PGTC) Seizures

Percent change from baseline is calculated as the number of seizures by week during the Double-Blind Treatment Phase (Treatment Week 1 up to Week 19) compared to the number of seizures per week during the Baseline Phase (Baseline Week 1 up to Week 8). A positive number equals a reduction in seizure frequency. PGTC seizures are more commonly known as gran mal seizures.

Change in seizure frequency was calculated as the average seizure frequency during each of the following: the Entire DB Treatment Phase (Treatment Week 1 up to Week 19); the Escalation Phase (Treatment Week 1 up to Week 7); the Maintenance Phase (Treatment Week 8 up to Week 19); and the last 8 weeks of the Maintenance Phase (Treatment Week 12 up to Week 19), minus the seizure frequency at Baseline.

Percent change from baseline is calculated as the number of seizures by week during the Escalation Phase (Treatment Week 1 up to Week 7), the Maintenance Phase (Treatment Week 8 up to Week 19), and during the last 8 weeks of the Maintenance Phase (Treatment Week 12 up to Week 19) compared to the number of seizures per week during the Baseline Phase (Baseline Week 1 up to Week 8). A positive number equals a reduction in seizure frequency.

50% reduction in seizure frequency is defined as the time at which a participant first achieved and maintained a \>=50% reduction in seizure frequency following exposure to at least 1 week of study drug.

Change from baseline in body weight is calculated as the Week 19 (or last on-study measurement in Double-Blind Treatment Phase) value minus the Baseline value.

The investigators rated the participants' overall clinical status based on 7 clinical factors and an overall factor: seizure frequency, duration, and intensity; adverse experiences; social, intellectual, and motor functioning. Using a 7-point scale (marked deterioration \[1\], moderate deterioration \[2\], mild deterioration \[3\], no change \[4\], mild improvement \[5\], moderate improvement \[6\], or marked improvement \[7\]), the investigators assessed the participants' status compared to their condition prior to initiating study medication.

Participants were asked to rate their satisfaction with their seizure control compared to their seizure control prior to initiating study drug on a 7 point scale: marked deterioration (1), moderate deterioration (2), mild deterioration (3), no change (4), mild improvement (5), moderate improvement (6), or marked improvement (7).

Percent change from baseline is calculated as the number of seizures by week during the entire CP (CP Week 1 up to Week 52), the Transition Phase (CP Week 1 up to Week 7), the Open-Label Phase (CP Week 8 up to Week 52), and the last 8 weeks of the Open-Label Phase (CP Week 45 up to Week 52) minus the number of seizures per week during the Baseline Phase (Baseline Week 1 through Week 8). A positive number equals a reduction in seizure frequency.

Change in seizure frequency was calculated as the average seizure frequency during each of the following: the Entire CP (CP Week 1 up to Week 52); the Transition Phase (CP Week 1 up to Week 7); the Open-Label (OL) Phase (CP Week 8 up to Week 52); and the last 8 weeks of the Open Label Phase (CP Week 45 up to Week 52) minus the seizure frequency at Baseline. W, Week.

The POMS is a self-administered 65-item questionnaire that evaluates the participants' perception of their mood state in 6 areas: tension-anxiety, depression-dejection, anger-hostility, vigor-activity, fatigue-inertia, and confusion-bewilderment. Items are rated on a 5-point Likert scale from 0 (not at all) to 4 (extremely), with higher scores indicating a more negative mood state. A total score (from 0 to 24) is obtained by summing the scores of the six domains.

The 20-item CES-D questionnaire is self-administered and asks respondents to report the frequency to which the 20 events were experienced over the past week. A 4-point Likert scale is used and ranges from rarely or none of the time (0) to most or all of the time (3). The total score, a sum across the 20 items (ranging from 0 to 60), determines the extent to which a participant may be experiencing depression. Higher scores indicate a higher severity of depression.

The NDDI-E is a self-reported questionnaire composed of 46 brief phrases/words to identify mood disorders across the spectrum of depression. It was developed to capture depressive moods that are co-morbid with the disease of epilepsy or its treatment as well as to measure the depressive state of the participant. All phrases are measured on a 4-point Likert scale of Never (1) to Always/often (4) and refer to the participants' mood over the past week. Scoring is comprised of a total mood score calculated by summing the scores of 6 specific items (from 6=never to 24=always or often).

The QOLIE-31 is a 31-item questionnaire that evaluates the participants' perception of his or her quality of life in 7 domains: seizure worry, emotional well being, energy/fatigue, cognitive functioning, medication effects, social functioning, and overall quality of life. Each domain (with scores ranging from 0 to 100) is summed and divided by the total number of questions that were answered. The overall score is derived by weighting and then summing up the seven domain scores.

The AEP is a list of 19 items covering many possible side effects attributable to drug treatment. The participants respond by assessing how much each event has been a problem for them over the past 4 weeks (1=Never a Problem to 4=Always a Problem). Each individual item can be examined; an overall adverse events score is calculated as the sum of the scores across the 19 items. The AEP total score ranges from 19 to 76, with a higher score indicating a higher degree of adverse event severity.

The SSQ is a self-reported instrument developed to assess the severity of seizures and seizure symptoms. The scale consists of 10 major clinical features/symptoms of seizures that the participants rate on a 7-point Likert scale (ranging from very mild/helpful/no bother at all \[1\] to very severe/no help/bothersome \[7\]). The Global Bother Domain is the primary score used for the analysis of the SSQ and has scores ranging from 1 to 7.

The ESS is an 8-item, self-administered questionnaire that measures excessive daytime sleepiness in adults. The instrument captures information on the extent to which the participant would be likely, or not, to fall asleep in certain situations. The stimulus question is: How likely are you to doze off or fall asleep in the following situations, in contrast to feeling just tired? Questions are answered on a 4-point scale (would never doze \[0\] to high chance of dozing \[3\]). The total score ranges from 0 to 24, where a higher score indicates a higher chance of dozing.

Serum samples for participants on lamotrigine were analyzed with a validated analytical method based on solid phase extraction of serum followed by High-Performance Liquid Chromatography (HPLC) Mass Spectrometry (MS)/MS analysis. The lower limit of quantification (LLQ) for serum lamotrigine was 4 nanograms (ng)/milliliter (mL), using a 50 microliter (µL) aliquot of human serum with a higher limit of quantification (HLQ) of 4,000 ng/mL. PK data cannot be reported, as PK data from several different studies have been combined into one POP/PK analysis and cannot be separated by study.