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

A Multicenter, Double-blind, Randomized, Parallel-group Evaluation of LAMICTAL Extended-Release Adjunctive Therapy in Patients With Primary Generalized Tonic-Clonic Seizures

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00104416
Enrollment
153
Registered
2005-03-01
Start date
2004-12-31
Completion date
2008-07-31
Last updated
2017-01-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Epilepsy, Tonic-Clonic

Keywords

antiepileptic drugs, seizures, primary generalized tonic-clonic seizures, Epilepsy, lamotrigine, anticonvulsants, LAMICTAL

Brief summary

This study is being conducted to compare the efficacy and safety of LAMICTAL (lamotrigine) extended-release with placebo in the treatment of Primary Generalized Tonic-Clonic (PGTC) seizures. LAMICTAL extended-release is an investigational drug. Placebo tablets look like LAMICTAL extended-release tablets but do not contain active medication. In this study, LAMICTAL extended-release or placebo tablets will be added to current seizure treatments.

Interventions

DRUGlamotrigine (LAMICTAL) extended-release

Primary experimental dosage form

DRUGPlacebo

Placebo control

Sponsors

GlaxoSmithKline
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
13 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Is ≥13 years of age (male or female). * Has a confident diagnosis of epilepsy with PGTC seizures for more than 24 weeks prior to the Baseline Phase. * Has electroencephalogram (EEG) evidence of either spike-and-wave discharges consistent with PGTC, or at least 2 EEGs with no indication of focal abnormalities. The EEG may be historical or prospective. Investigators may use a historical EEG as long as there is appropriate documentation. * Has a documented history of PGTC seizures with or without other generalized seizure type(s) with no focal onset, and at least 1 PGTC seizure during the eight consecutive weeks (i.e., 56 consecutive days) prior to starting the 8-week Baseline Phase. * Has at least 3 PGTC seizures occurring anytime during an 8-week (i.e., 56 days) prospective Baseline Phase. * NOTE: When a historical baseline is used, the same time period cannot count for documentation of inclusion criteria 4 and 5. Additionally, innumerable seizure activity will not count towards the number of seizures required for randomization. * NOTE: With authorization from GSK, a maximum of four weeks (i.e., 28 days) of historical seizure data may replace up to four weeks (i.e., 28 days) of the prospective Baseline Phase for subjects providing reliable documentation of the following: 1. complete daily seizure diary that includes the number of seizures experienced each day along with the exact classification of each seizure type for consecutive days prior to the prospective Baseline Phase 2. stability of prescribed dosages of background antiepileptic drugs (AEDs) 3. compliance with background AEDs. * All subjects permitted to use historical seizure data must complete a minimum of four weeks (i.e., 28 days) of the prospective Baseline Phase. The historical Baseline Phase and the prospective Baseline Phase must equal 56 consecutive days. * Is currently treated with a stable regimen of one or two AED(s) for at least four weeks prior to starting the Baseline Phase (historical or prospective). * NOTE: Benzodiazepines used chronically will be considered to be concurrent AEDs. * NOTE: Subjects with surgically implanted vagal nerve stimulators (VNS) will be allowed to enter the study provided that all of the following conditions are met: 1. VNS has been in place for at least 24 weeks prior to the Baseline Phase. 2. The settings must remain the same for at least 28 days prior to the Baseline Phase. 3. The settings must remain the same during the Baseline, Escalation, Maintenance and Transition Phases. 4. The battery is expected to last for the duration of the study. 5. VNS is counted as a concurrent AED. * Is able and willing to maintain an accurate and complete daily written seizure diary, or has a parent/caregiver who is able and willing to maintain an accurate and complete daily written seizure diary for the entire duration of the study. * Is able to comply with dosing of study drugs, background AEDs and all study procedures. * Has given written informed consent, or has a parent/legally authorized representative who has given written informed consent, prior to the performance of any study assessments. * If female, and of childbearing potential, must be using an acceptable form of birth control, to include one of the following: 1. Complete abstinence from intercourse for two weeks before exposure to the study drug, throughout the clinical trial, and for a period after the trial to account for elimination of the drug (a minimum of 3 weeks). 2. Consistent and correct use of one of the following methods of birth control: * Male partner who is sterile prior to the female subject's entry into the study and is the sole sexual partner for that female subject * Implants of levonorgestrel * Injectable progestogen * Oral contraceptive (either combined, with at least 50mcg estrogen for women on enzyme-induced AEDs, or progestogen only) * Any intrauterine device (IUD) with a documented failure rate of less than 1% per year * Double barrier method consisting of spermicide plus a mechanical barrier (e.g., spermicide plus a male condom or a female diaphragm). * NOTE: Women who have had a hysterectomy, tubal ligation, or are post-menopausal are considered to be of non-childbearing potential.

Exclusion criteria

* Has a history of partial seizures or interictal expression of partial seizures as evidenced by EEG NOTE: EEG may be historical or prospective. * Has had status epilepticus within the 24 weeks prior to, or during, the Baseline Phase. * Is taking three or more background AEDs chronically. * Has Lennox-Gastaut syndrome. * Is currently using or has previously used lamotrigine. * Is currently taking felbamate. * Is abusing alcohol and/or other substance(s). * Has taken an investigational drug within the previous 30 days or plans to take an investigational drug anytime during the study. * Is receiving chronic treatment with any medication that could influence seizure control. NOTE: Use of benzodiazepines is allowed. * Is currently following the ketogenic diet. * Is planning surgery to control seizures during the study. * Is suffering from acute or progressive neurological disease, severe psychiatric disease, or severe mental abnormality that are likely to interfere with the objectives of the study. * Has any clinically significant cardiac, renal, hepatic condition, or a condition that affects the absorption, distribution, metabolism or excretion of drugs. * Is pregnant, breastfeeding, or planning to become pregnant during the study or within the three weeks after the last dose of study drug.

Design outcomes

Primary

MeasureTime frameDescription
Percent Change From Baseline in Weekly Primary Generalized Tonic-clonic (PGTC) Seizure Frequency During the Entire Double-Blind Treatment PhaseBaseline through end of Double-Blind Treatment Phase (up to Week 19)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.

Secondary

MeasureTime frameDescription
Percent Change From Baseline in PGTC Seizure Frequency During the Escalation Phase, the Maintenance Phase, and During the Last 8 Weeks of the Maintenance Phase of the Double-Blind Treatment PhaseEscalation Phase (Treatment Week 1 up to Week 7), Maintenance Phase (Treatment Week 8 up to Week 19), and the last 8 weeks of the Maintenance Phase (Week 12 up to Week 19)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.
Number of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment PhaseBaseline through end of Double-Blind Treatment Phase (up to Week 19)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 at Week 19 of the Double-Blind Treatment PhaseBaseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)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.
Number of Participants With Improved Clinical Status on the Investigator's Global Assessment in the Double-Blind Treatment PhaseWeek 19 (or last on-study assessment in Double-Blind Treatment Phase)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.
Number of Participants With Improved Satisfaction With Seizure Control on the Subject Satisfaction Questionnaire in the Double-Blind Treatment PhaseWeek 19 (or last on-study assessment in Double-Blind Treatment Phase)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 in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseEntire 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)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.
Number of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.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)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.
Number of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance PhaseEntire DB Treatment Phase (Treatment Week 1 up to Week 19), Escalation Phase (Treatment Week 1 up to Week 7), 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)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.
Mean Change From Baseline in the Center for Epidemiological Studies-Depression Scale (CES-D) Total Score at Week 19 of the Double-Blind Treatment PhaseBaseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)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.
Mean Change From Baseline in the Neurological Disorders Depression Inventory-Epilepsy (NDDI-E) 6-Item Total Score at Week 19 of the Double-Blind Treatment PhaseBaseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)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).
Mean Change From Baseline in the Quality of Life in Epilepsy-31-P (QOLIE-31P) Overall Score at Week 19 of the Double-Blind Treatment PhaseBaseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)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.
Mean Change From Baseline in the Adverse Experience Profile (AEP) Total Score at Week 19 of the Double-Blind Treatment PhaseBaseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)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.
Mean Change From Baseline in the Seizure Severity Questionnaire (SSQ) Global Bother Score at Week 19 Double-Blind Treatment PhaseBaseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)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.
Mean Change From Baseline in the Epworth Sleepiness Scale (ESS) 8-Item Total Score at Week 19 of the Double-Blind Treatment PhaseBaseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)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 Concentrations and Population (POP) Pharmacokinetic Parameters for LamotrigineBlood samples drawn at Treatment Weeks 11, 15, and 19 (or last on-study measurement in Double-Blind Treatment Phase)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.
Mean Change From Baseline in the Profile of Mood State (POMS) Mood Disturbance Total Score at Week 19 of the Double-Blind Treatment PhaseBaseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)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.

Countries

Argentina, Brazil, Chile, Germany, India, Malaysia, Puerto Rico, Russia, South Korea, Ukraine, United States

Participant flow

Recruitment details

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.

Pre-assignment details

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.

Participants by arm

ArmCount
Double-Blind Phase: Placebo
Control - matching placebo once daily
73
Double-Blind Phase: LTG XR
LTG XR once daily
70
Total143

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003FG004
Continuation PhaseAdverse Event00202
Continuation PhaseLost to Follow-up00101
Continuation PhaseNon-compliance00001
Continuation PhasePregnancy00110
Continuation PhaseWithdrawal by Subject00211
Double-Blind PhaseAdverse Event21000
Double-Blind PhaseLost to Follow-up01000
Double-Blind PhaseParticipant Did Not Take Drug34000
Double-Blind PhasePregnancy10000
Double-Blind PhaseProtocol Violation01000
Double-Blind PhaseWithdrawal by Subject23000

Baseline characteristics

CharacteristicTotalDouble-Blind Phase: PlaceboDouble-Blind Phase: LTG XR
Age, Continuous28.9 years
STANDARD_DEVIATION 12.1
28.4 years
STANDARD_DEVIATION 11.48
29.4 years
STANDARD_DEVIATION 12.78
Gender
Female
70 Participants38 Participants32 Participants
Gender
Male
73 Participants35 Participants38 Participants
Race/Ethnicity, Customized
African American/African Heritage
3 participants1 participants2 participants
Race/Ethnicity, Customized
American Indian or Alaskan Native and White
2 participants2 participants0 participants
Race/Ethnicity, Customized
Asian
62 participants31 participants31 participants
Race/Ethnicity, Customized
Asian and White
1 participants1 participants0 participants
Race/Ethnicity, Customized
White
75 participants38 participants37 participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
deaths
Total, all-cause mortality
— / —— / —— / —— / —— / —
other
Total, other adverse events
21 / 7427 / 7229 / 6921 / 6718 / 32
serious
Total, serious adverse events
0 / 741 / 723 / 693 / 671 / 32

Outcome results

Primary

Percent Change From Baseline in Weekly Primary Generalized Tonic-clonic (PGTC) Seizure Frequency During the Entire Double-Blind Treatment Phase

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.

Time frame: Baseline through end of Double-Blind Treatment Phase (up to Week 19)

Population: Intent-to-Treat (ITT) Population: all randomized participants who took at least one dose of study drug and had at least one post-baseline efficacy assessment in the Double-Blind Treatment Phase. One participant in each treatment group did not have any PGTC seizures during the Baseline Phase.

ArmMeasureValue (MEDIAN)
Double-Blind Phase: PlaceboPercent Change From Baseline in Weekly Primary Generalized Tonic-clonic (PGTC) Seizure Frequency During the Entire Double-Blind Treatment Phase32.1 percent change
Double-Blind Phase: LTG XRPercent Change From Baseline in Weekly Primary Generalized Tonic-clonic (PGTC) Seizure Frequency During the Entire Double-Blind Treatment Phase75.4 percent change
p-value: <0.000195% CI: [15.8, 48.1]Cochran-Mantel-Haenszel
Secondary

Change From Baseline in Body Weight at Week 19 of the Double-Blind Treatment Phase

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.

Time frame: Baseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: ITT Population

ArmMeasureValue (MEDIAN)
Double-Blind Phase: PlaceboChange From Baseline in Body Weight at Week 19 of the Double-Blind Treatment Phase1.00 kilograms
Double-Blind Phase: LTG XRChange From Baseline in Body Weight at Week 19 of the Double-Blind Treatment Phase0.00 kilograms
Secondary

Mean Change From Baseline in the Adverse Experience Profile (AEP) Total Score at Week 19 of the Double-Blind Treatment Phase

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.

Time frame: Baseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: ITT Population. The questionnaire was not completed by 65 participants in both the Placebo and LTG XR groups. Only participants completing the questionnaire were included in the analysis of this outcome measure.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Double-Blind Phase: PlaceboMean Change From Baseline in the Adverse Experience Profile (AEP) Total Score at Week 19 of the Double-Blind Treatment Phase3.0 points on a scaleStandard Error 2.16
Double-Blind Phase: LTG XRMean Change From Baseline in the Adverse Experience Profile (AEP) Total Score at Week 19 of the Double-Blind Treatment Phase1.4 points on a scaleStandard Error 2.77
Secondary

Mean Change From Baseline in the Center for Epidemiological Studies-Depression Scale (CES-D) Total Score at Week 19 of the Double-Blind Treatment Phase

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.

Time frame: Baseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: ITT Population. The questionnaire was not completed by 64 and 59 participants in the Placebo and LTG XR groups, respectively. Only participants completing the questionnaire were included in the analysis of this outcome measure.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Double-Blind Phase: PlaceboMean Change From Baseline in the Center for Epidemiological Studies-Depression Scale (CES-D) Total Score at Week 19 of the Double-Blind Treatment Phase2.9 points on a scaleStandard Error 2.81
Double-Blind Phase: LTG XRMean Change From Baseline in the Center for Epidemiological Studies-Depression Scale (CES-D) Total Score at Week 19 of the Double-Blind Treatment Phase2.4 points on a scaleStandard Error 2.54
Secondary

Mean Change From Baseline in the Epworth Sleepiness Scale (ESS) 8-Item Total Score at Week 19 of the Double-Blind Treatment Phase

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.

Time frame: Baseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: ITT Population. The questionnaire was not completed by 55 and 51 participants in the Placebo and LTG XR groups, respectively. Only participants completing the questionnaire were included in the analysis of this outcome measure.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Double-Blind Phase: PlaceboMean Change From Baseline in the Epworth Sleepiness Scale (ESS) 8-Item Total Score at Week 19 of the Double-Blind Treatment Phase-0.6 points on a scaleStandard Error 0.69
Double-Blind Phase: LTG XRMean Change From Baseline in the Epworth Sleepiness Scale (ESS) 8-Item Total Score at Week 19 of the Double-Blind Treatment Phase1.0 points on a scaleStandard Error 0.67
Secondary

Mean Change From Baseline in the Neurological Disorders Depression Inventory-Epilepsy (NDDI-E) 6-Item Total Score at Week 19 of the Double-Blind Treatment Phase

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).

Time frame: Baseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: ITT Population. The questionnaire was not completed by 65 participants in both the Placebo and LTG XR groups. Only participants completing the questionnaire were included in the analysis of this outcome measure.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Double-Blind Phase: PlaceboMean Change From Baseline in the Neurological Disorders Depression Inventory-Epilepsy (NDDI-E) 6-Item Total Score at Week 19 of the Double-Blind Treatment Phase-0.1 points on a scaleStandard Error 0.98
Double-Blind Phase: LTG XRMean Change From Baseline in the Neurological Disorders Depression Inventory-Epilepsy (NDDI-E) 6-Item Total Score at Week 19 of the Double-Blind Treatment Phase-2.4 points on a scaleStandard Error 1.24
Secondary

Mean Change From Baseline in the Profile of Mood State (POMS) Mood Disturbance Total Score at Week 19 of the Double-Blind Treatment Phase

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.

Time frame: Baseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: ITT Population. The questionnaire was not completed by 53 and 57 participants in the Placebo and LTG XR groups, respectively. Only participants completing the questionnaire were included in the analysis of this outcome measure.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Double-Blind Phase: PlaceboMean Change From Baseline in the Profile of Mood State (POMS) Mood Disturbance Total Score at Week 19 of the Double-Blind Treatment Phase2.4 points on a scaleStandard Error 6.97
Double-Blind Phase: LTG XRMean Change From Baseline in the Profile of Mood State (POMS) Mood Disturbance Total Score at Week 19 of the Double-Blind Treatment Phase9.7 points on a scaleStandard Error 8.65
Secondary

Mean Change From Baseline in the Quality of Life in Epilepsy-31-P (QOLIE-31P) Overall Score at Week 19 of the Double-Blind Treatment Phase

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.

Time frame: Baseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: ITT Population. The questionnaire was not completed by 55 participants in both the Placebo and LTG XR groups. Only participants completing the questionnaire were included in the analysis of this outcome measure.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Double-Blind Phase: PlaceboMean Change From Baseline in the Quality of Life in Epilepsy-31-P (QOLIE-31P) Overall Score at Week 19 of the Double-Blind Treatment Phase-6.5 points on a scaleStandard Error 3.97
Double-Blind Phase: LTG XRMean Change From Baseline in the Quality of Life in Epilepsy-31-P (QOLIE-31P) Overall Score at Week 19 of the Double-Blind Treatment Phase-8.5 points on a scaleStandard Error 4.35
Secondary

Mean Change From Baseline in the Seizure Severity Questionnaire (SSQ) Global Bother Score at Week 19 Double-Blind Treatment Phase

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.

Time frame: Baseline and Week 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: ITT Population. The questionnaire was not completed by 68 and 67 participants in the Placebo and LTG XR groups, respectively. Only participants completing the questionnaire were included in the analysis of this outcome measure.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Double-Blind Phase: PlaceboMean Change From Baseline in the Seizure Severity Questionnaire (SSQ) Global Bother Score at Week 19 Double-Blind Treatment Phase0.86 points on a scaleStandard Error 0.84
Double-Blind Phase: LTG XRMean Change From Baseline in the Seizure Severity Questionnaire (SSQ) Global Bother Score at Week 19 Double-Blind Treatment Phase1.23 points on a scaleStandard Error 1.08
Secondary

Number of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase

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.

Time frame: Entire DB Treatment Phase (Treatment Week 1 up to Week 19), Escalation Phase (Treatment Week 1 up to Week 7), 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)

Population: ITT Population. One participant in each treatment group did not have any PGTC seizures during the Baseline Phase, as a result they were not counted in this efficacy endpoint; an additional 2 and 1 participants in the Placebo and LTG XR group, respectively, were not counted in the Maintenance Phase (MP) or last 8 weeks of MP due to study withdrawal.

ArmMeasureGroupValue (NUMBER)
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=25% reduction, Entire DB TP, n=72, 6943 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=75% reduction, Entire DB TP, n=72, 6914 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase100% reduction, Entire DB TP, n=72, 697 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=75% reduction, Escalation Phase, n=72, 6914 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=25% reduction, Maintenance Phase, n=70, 6846 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=75% reduction, Maintenance Phase, n=70, 6814 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=50% reduction, Entire DB TP, n=72, 6923 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=25% reduction, Escalation Phase, n=72, 6939 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=50% reduction, Escalation Phase, n=72, 6923 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase100% reduction, Escalation Phase, n=72, 699 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=50% reduction, Maintenance Phase, n=70, 6829 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase100% reduction, Maintenance Phase, n=70, 6810 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=25% reduction, Last 8 Weeks of MP, n=70, 6847 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=50% reduction, Last 8 Weeks of MP, n=70, 6829 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=75% reduction, Last 8 Weeks of MP, n=70, 6818 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase100% reduction, Last 8 Weeks of MP, n=70, 6815 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase100% reduction, Entire DB TP, n=72, 6914 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=25% reduction, Entire DB TP, n=72, 6956 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=50% reduction, Entire DB TP, n=72, 6948 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=25% reduction, Maintenance Phase, n=70, 6860 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=50% reduction, Last 8 Weeks of MP, n=70, 6854 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=25% reduction, Escalation Phase, n=72, 6951 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=50% reduction, Escalation Phase, n=72, 6938 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=75% reduction, Escalation Phase, n=72, 6924 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=50% reduction, Maintenance Phase, n=70, 6851 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=75% reduction, Last 8 Weeks of MP, n=70, 6844 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=75% reduction, Maintenance Phase, n=70, 6840 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase100% reduction, Maintenance Phase, n=70, 6831 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=25% reduction, Last 8 Weeks of MP, n=70, 6861 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase100% reduction, Last 8 Weeks of MP, n=70, 6835 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase100% reduction, Escalation Phase, n=72, 6915 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction in PGTC Seizure Frequency During the Entire Double-Blind (DB)Treatment Phase (TP), the Escalation Phase, the Maintenance Phase, and the Last 8 Weeks of the Maintenance Phase>=75% reduction, Entire DB TP, n=72, 6935 participants
Secondary

Number of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.

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.

Time frame: 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)

Population: ITT Population for CP. Variability in participant numbers are due to not having any PGTC seizures during the Baseline Phase and study withdrawal prior to progressing to the next phase.

ArmMeasureGroupValue (NUMBER)
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Entire CP, n=68, 66, 242 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Open-Label Phase, n=68, 64, 232 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Entire CP, n=68, 66, 2416 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Last 8 W of OL Phase,n=68, 63, 1945 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Open-Label Phase, n=68, 64, 2321 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Entire CP, n=68, 66, 2459 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Transition Phase, n=68, 66, 2033 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Entire CP, n=68, 66, 2446 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Last 8 W of OL Phase, n=68, 63, 1935 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Transition Phase, n=68, 66, 2027 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Last 8 W of OL Phase,n=68, 63, 1960 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Transition Phase, n=68, 66, 203 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Transition Phase, n=68, 66, 2044 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Open-Label Phase, n=68, 64, 2361 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Last 8 W of OL Phase, n=68, 63, 192 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Entire CP, n=68, 66, 2457 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Open-Label Phase, n=68, 64, 2356 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Last 8 W of OL Phase,n=68, 63, 1953 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Open-Label Phase, n=68, 64, 2347 participants
Double-Blind Phase: PlaceboNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Transition Phase, n=68, 66, 2051 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Open-Label Phase, n=68, 64, 2349 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Open-Label Phase, n=68, 64, 231 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Entire CP, n=68, 66, 2449 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Last 8 W of OL Phase,n=68, 63, 1953 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Last 8 W of OL Phase,n=68, 63, 1947 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Entire CP, n=68, 66, 2428 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Last 8 W of OL Phase, n=68, 63, 1941 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Open-Label Phase, n=68, 64, 2357 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Last 8 W of OL Phase, n=68, 63, 191 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Entire CP, n=68, 66, 241 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Open-Label Phase, n=68, 64, 2328 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Last 8 W of OL Phase,n=68, 63, 1960 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Transition Phase, n=68, 66, 2056 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Transition Phase, n=68, 66, 2046 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Entire CP, n=68, 66, 2463 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Transition Phase, n=68, 66, 2041 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Transition Phase, n=68, 66, 201 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Open-Label Phase, n=68, 64, 2361 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Entire CP, n=68, 66, 2459 participants
Double-Blind Phase: LTG XRNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Transition Phase, n=68, 66, 2060 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Last 8 W of OL Phase, n=68, 63, 194 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Transition Phase, n=68, 66, 2012 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Entire CP, n=68, 66, 2411 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Entire CP, n=68, 66, 2411 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Entire CP, n=68, 66, 248 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Entire CP, n=68, 66, 246 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Entire CP, n=68, 66, 2410 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Transition Phase, n=68, 66, 2013 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Transition Phase, n=68, 66, 2012 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Transition Phase, n=68, 66, 2012 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Transition Phase, n=68, 66, 203 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Open-Label Phase, n=68, 64, 2312 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Open-Label Phase, n=68, 64, 2310 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Open-Label Phase, n=68, 64, 238 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Open-Label Phase, n=68, 64, 236 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% increase, Open-Label Phase, n=68, 64, 2310 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=25% reduction, Last 8 W of OL Phase,n=68, 63, 1910 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=50% reduction, Last 8 W of OL Phase,n=68, 63, 1910 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.>=75% reduction, Last 8 W of OL Phase,n=68, 63, 1910 participants
Baseline FailuresNumber of Participants With >=25%, >=50%, >=75%, or 100% Reduction or >=50% Increase From Baseline in Weekly PGTC Seizure Frequency for the Entire Continuation Phase, the Transition Phase, the Open-Label (OL) Phase, and the Last 8 Weeks of the OL Phase.100% reduction, Last 8 W of OL Phase, n=68, 63, 1910 participants
Secondary

Number of Participants With Improved Clinical Status on the Investigator's Global Assessment in the Double-Blind Treatment Phase

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.

Time frame: Week 19 (or last on-study assessment in Double-Blind Treatment Phase)

Population: ITT Population. Overall clinical status not assessed for 2 participants in each of the Placebo and LTG XR groups, respectively.

ArmMeasureGroupValue (NUMBER)
Double-Blind Phase: PlaceboNumber of Participants With Improved Clinical Status on the Investigator's Global Assessment in the Double-Blind Treatment PhaseNo change, score of 433 participants
Double-Blind Phase: PlaceboNumber of Participants With Improved Clinical Status on the Investigator's Global Assessment in the Double-Blind Treatment PhaseAny deterioration, score of 1-32 participants
Double-Blind Phase: PlaceboNumber of Participants With Improved Clinical Status on the Investigator's Global Assessment in the Double-Blind Treatment PhaseAny improvement, score of 5-736 participants
Double-Blind Phase: LTG XRNumber of Participants With Improved Clinical Status on the Investigator's Global Assessment in the Double-Blind Treatment PhaseAny improvement, score of 5-757 participants
Double-Blind Phase: LTG XRNumber of Participants With Improved Clinical Status on the Investigator's Global Assessment in the Double-Blind Treatment PhaseNo change, score of 410 participants
Double-Blind Phase: LTG XRNumber of Participants With Improved Clinical Status on the Investigator's Global Assessment in the Double-Blind Treatment PhaseAny deterioration, score of 1-31 participants
Secondary

Number of Participants With Improved Satisfaction With Seizure Control on the Subject Satisfaction Questionnaire in the Double-Blind Treatment Phase

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).

Time frame: Week 19 (or last on-study assessment in Double-Blind Treatment Phase)

Population: ITT Population. Participant satisfaction was not assessed for 2 participants in each of the Placebo and LTG XR groups, respectively.

ArmMeasureGroupValue (NUMBER)
Double-Blind Phase: PlaceboNumber of Participants With Improved Satisfaction With Seizure Control on the Subject Satisfaction Questionnaire in the Double-Blind Treatment PhaseAny improvement, score of 5-753 participants
Double-Blind Phase: PlaceboNumber of Participants With Improved Satisfaction With Seizure Control on the Subject Satisfaction Questionnaire in the Double-Blind Treatment PhaseNo change, score of 413 participants
Double-Blind Phase: PlaceboNumber of Participants With Improved Satisfaction With Seizure Control on the Subject Satisfaction Questionnaire in the Double-Blind Treatment PhaseAny deterioration, score of 1-35 participants
Double-Blind Phase: LTG XRNumber of Participants With Improved Satisfaction With Seizure Control on the Subject Satisfaction Questionnaire in the Double-Blind Treatment PhaseAny improvement, score of 5-760 participants
Double-Blind Phase: LTG XRNumber of Participants With Improved Satisfaction With Seizure Control on the Subject Satisfaction Questionnaire in the Double-Blind Treatment PhaseAny deterioration, score of 1-32 participants
Double-Blind Phase: LTG XRNumber of Participants With Improved Satisfaction With Seizure Control on the Subject Satisfaction Questionnaire in the Double-Blind Treatment PhaseNo change, score of 46 participants
Secondary

Number of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase

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.

Time frame: Baseline through end of Double-Blind Treatment Phase (up to Week 19)

Population: ITT Population

ArmMeasureGroupValue (NUMBER)
Double-Blind Phase: PlaceboNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase8 weeks14 participants
Double-Blind Phase: PlaceboNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase12 weeks20 participants
Double-Blind Phase: PlaceboNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase2 weeks12 participants
Double-Blind Phase: PlaceboNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase16 weeks23 participants
Double-Blind Phase: PlaceboNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase4 weeks12 participants
Double-Blind Phase: LTG XRNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase16 weeks48 participants
Double-Blind Phase: LTG XRNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase4 weeks28 participants
Double-Blind Phase: LTG XRNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase2 weeks22 participants
Double-Blind Phase: LTG XRNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase8 weeks39 participants
Double-Blind Phase: LTG XRNumber of Participants With the Indicated Time to >=50% Reduction in Seizure Frequency in the Double-Blind Treatment Phase12 weeks43 participants
Secondary

Percent Change From Baseline in PGTC Seizure Frequency During the Escalation Phase, the Maintenance Phase, and During the Last 8 Weeks of the Maintenance Phase of the Double-Blind Treatment Phase

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.

Time frame: Escalation Phase (Treatment Week 1 up to Week 7), Maintenance Phase (Treatment Week 8 up to Week 19), and the last 8 weeks of the Maintenance Phase (Week 12 up to Week 19)

Population: ITT Population. One participant in each treatment group did not have any PGTC seizures during the Baseline Phase as a result they were not counted for this efficacy endpoint; an additional 2 and 1 participants in the Placebo and LTG XR group, respectively, were not counted in the Maintenance Phase (MP) or last 8 weeks of MP due to study withdrawal.

ArmMeasureGroupValue (MEDIAN)
Double-Blind Phase: PlaceboPercent Change From Baseline in PGTC Seizure Frequency During the Escalation Phase, the Maintenance Phase, and During the Last 8 Weeks of the Maintenance Phase of the Double-Blind Treatment PhaseEscalation Phase, n=72, 6930.6 percent change
Double-Blind Phase: PlaceboPercent Change From Baseline in PGTC Seizure Frequency During the Escalation Phase, the Maintenance Phase, and During the Last 8 Weeks of the Maintenance Phase of the Double-Blind Treatment PhaseMaintenance Phase, n=70, 6833.3 percent change
Double-Blind Phase: PlaceboPercent Change From Baseline in PGTC Seizure Frequency During the Escalation Phase, the Maintenance Phase, and During the Last 8 Weeks of the Maintenance Phase of the Double-Blind Treatment PhaseLast 8 weeks of the Maintenance Phase, n=70, 6835.4 percent change
Double-Blind Phase: LTG XRPercent Change From Baseline in PGTC Seizure Frequency During the Escalation Phase, the Maintenance Phase, and During the Last 8 Weeks of the Maintenance Phase of the Double-Blind Treatment PhaseEscalation Phase, n=72, 6961.9 percent change
Double-Blind Phase: LTG XRPercent Change From Baseline in PGTC Seizure Frequency During the Escalation Phase, the Maintenance Phase, and During the Last 8 Weeks of the Maintenance Phase of the Double-Blind Treatment PhaseMaintenance Phase, n=70, 6889.7 percent change
Double-Blind Phase: LTG XRPercent Change From Baseline in PGTC Seizure Frequency During the Escalation Phase, the Maintenance Phase, and During the Last 8 Weeks of the Maintenance Phase of the Double-Blind Treatment PhaseLast 8 weeks of the Maintenance Phase, n=70, 68100.0 percent change
Secondary

Percent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label Phase

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.

Time frame: 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)

Population: ITT Population for CP: all participants who took at least one dose of study medication during the CP and had at least one post baseline seizure assessment during the CP. Variability in participant numbers are due to not having any PGTC seizures during the Baseline Phase and study withdrawal prior to progressing to the next phase.

ArmMeasureGroupValue (MEDIAN)
Double-Blind Phase: PlaceboPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseEntire Continuation Phase, n=68, 66, 2485.2 percent change
Double-Blind Phase: PlaceboPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseTransition Phase, n=68, 66, 2073.1 percent change
Double-Blind Phase: PlaceboPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseOpen-Label Phase, n=68, 64, 2389.2 percent change
Double-Blind Phase: PlaceboPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseLast 8 weeks of Open-Label Phase, n=68, 63, 19100.0 percent change
Double-Blind Phase: LTG XRPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseTransition Phase, n=68, 66, 20100.0 percent change
Double-Blind Phase: LTG XRPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseEntire Continuation Phase, n=68, 66, 2495.1 percent change
Double-Blind Phase: LTG XRPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseLast 8 weeks of Open-Label Phase, n=68, 63, 19100.0 percent change
Double-Blind Phase: LTG XRPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseOpen-Label Phase, n=68, 64, 2395.0 percent change
Baseline FailuresPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseEntire Continuation Phase, n=68, 66, 2421.7 percent change
Baseline FailuresPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseOpen-Label Phase, n=68, 64, 2331.7 percent change
Baseline FailuresPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseTransition Phase, n=68, 66, 20100.0 percent change
Baseline FailuresPercent Change From Baseline in Weekly PGTC Seizure Frequency During the Entire Continuation Phase (CP), the Transition Phase, the Open-Label Phase, and the Last 8 Weeks of the Open-Label PhaseLast 8 weeks of Open-Label Phase, n=68, 63, 19100.0 percent change
Secondary

Serum Concentrations and Population (POP) Pharmacokinetic Parameters for Lamotrigine

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.

Time frame: Blood samples drawn at Treatment Weeks 11, 15, and 19 (or last on-study measurement in Double-Blind Treatment Phase)

Population: PK Population: Number of participants analyzed for 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.

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026