Faculty Bibliography

Rationale: WEPOD is a multicenter prospective observational study evaluating fertility among women with epilepsy (WWE) compared to healthy controls. WEPOD utilizes a customized mobile electronic patient diary on a commercially available mobile device (Apple's iPod Touch) . A customized diary application made by Irody tracks fertility information, and in WWE, seizures and daily medication use. The app delivers all patient captured information to a cloud database where it is analyzed. We determined the degree of data tracking adherence associated with dropping out of the study. Methods: WWE planning pregnancy enrolled within 6 months of stopping birth control. Subjects were trained to use a customized application (the WEPOD App) for daily data tracking. All subjects were asked to track data daily until delivery or up to 12 months if they did not become pregnant. Data were analyzed by percent of days in the study for which data was tracked. The cut point of percent tracking with the maximum sensitivity and specificity associating with dropping out of the study was determined. Further, the timing of dropping out of the study was evaluated. Results: Of 61 WWE who enrolled before 12/1/12 and tracked data, 9 subjects dropped out and 52 continued in the study. The overall adherence was 92.3%; 36/61 had 100% adherence. Mean percent adherence of the 52 completed subjects was 96.1% (median 100, range 33-100). Of the 9 subjects who dropped out, percent adherence was 6, 22, 55, 77, 86, 87, 90, 100 and 100 for a mean of 69.9 (median 86). Only 4 subjects were less than 90% tracking adherent and completed the study. The optimal percent adherence cut point for associating with dropping out of the study was 96.5% which had a sensitivity of 87% and a specificity of 83% (point A). Given that the cut point of 96.5 % adherence is higher than the overall mean adherence, and that specificity may be less important than sensitivity since other factors accounting for late drop outs are not accounted for, a more reasonabl!

Rationale: YKP3089, a tetrazole alkyl carbamate derivative, is a new investigational antiepileptic drug (AED) with a potentially unique mechanism of action. YKP3089 displayed activity in a broad array of screening models, including the LTG-resistant amygdala-kindled rat and the 6 Hz model. The exact mechanism of action is unclear, although it appears to enhance GABA-induced currents without binding to GABAA subunits. It is an inhibitor of the inactivated state of Na+ channels. In early clinical studies, YKP3089 demonstrated a PK profile suited to clinical use, including once-daily dosing. Plasma concentrations correlated with PD effect in the human photosensitivity model. This is the first Phase 2 randomized, doubleblind, placebo-controlled study of YKP3089 to assess efficacy and tolerability in patients with partial-onset seizures. Methods: Design: After an 8-wk baseline, patients were randomized to either placebo or YKP3089 titrated over 6 wks to 200 mg (50 mg increments at 2-wk intervals), followed by a 6-wk maintenance phase. Population: Adults with inadequately controlled partial-onset seizures (>3 seizures/month in baseline) despite therapy with 1-3 AEDs. Population for primary analyses was ITT. The primary endpoint was median % reduction from baseline 28-day seizure frequency. Secondary endpoints included 50% responder rate; % of study completers with no seizures in maintenance phase; and median % seizure reduction by seizure type. Results: ITT population: YKP3089, N=113; placebo, N=108. Mean ages: 36 yr (YKP3089) and 37 yr (placebo); gender: 51% female (YKP3089) and 46% female (placebo). At baseline, median 28-day seizure frequency was 7.5 (YKP3089) and 5.5 (placebo). In patients receiving YKP3089, median % seizure reduction was 55.6% vs 21.5% (P<0.0001) with placebo. The 50% responder rates were 50.4% and 22.2% (P<0.0001), for YKP3089 and placebo, respectively. Among study completers, 27.5% receiving YKP3089 and 9.1% receiving placebo had no seizures during the maintenance phase. Media!

Advances in MRI have transformed the in vivo detection of brain abnormalities in neurological disease. However, many subtle structural abnormalities remain undetected, especially in individual patients, where clinical relevance is highest. We present a quantitative, multifeature morphometry approach combined with machine learning algorithms for detecting structural cortical abnormalities in epilepsy patients with focal cortical dysplasia (FCD). FCD is a malformation of cortical development and is the most common etiology in pediatric epilepsy and the second most common etiology in adults with treatment resistant epilepsy. Lesions may occur anywhere in cortex. Seizure freedom after surgery is reported at 66% with a detected lesion, but only 29% in MRI-negative patients. Yet, 70% to 80% of histologically confirmed FCD cases go undetected by visual inspection of the MRI. Sixty-one controls and 23 MRI-negative patients in whom no focal lesion was detected during routine visual radiological analysis and 7 MRI-positive patients were scanned before surgery at 3 T using a T1-weighted MRI sequence. All patients subsequently underwent intracranial EEG monitoring and resection of the epileptic focus and pathology confirmed FCD. Morphometric routines with surface-based spherical averaging techniques were used to align anatomical structures between individual brains and to calculate 6 features at each vertex, including cortical thickness, gray-white contrast, local gyrification, sulcal depth, Jacobian distance, and curvature. A logistic regression classifier was trained on normal control data and the data from the FCD region of MRI-positive patients to classify, in MRI-negative patients, vertices into lesional and nonlesional. The logistic regression approach correctly classified lesions within the resection zone in 14 out of the 24 (58%) MRInegative patients. The overall false positive rate (by vertex) was never greater than 1.05%. Quantitative MRI can aid in the presurgical detection of FCD lesions, even !

Despite the expanding treatment options in the past two decades, a third of patients with epilepsy remain treatment resistant, and there is a continued need for new therapies. After many years of repeated success, several late-stage clinical development programs for antiseizure drugs have seen unexpected failures to demonstrate superiority of the experimental drug over placebo, which has led to a re-examination of how clinical trials are conducted in this heterogeneous and often unpredictable condition. There are numerous sources of variability in epilepsy trials that can reduce effect size. Methods to improve diagnostic accuracy and outcome assessment are needed to ensure that promising compounds have the best chance to get to patients. 2013 Future Science Ltd

Epileptic encephalopathies are a devastating group of severe childhood epilepsy disorders for which the cause is often unknown. Here we report a screen for de novo mutations in patients with two classical epileptic encephalopathies: infantile spasms (n = 149) and Lennox-Gastaut syndrome (n = 115). We sequenced the exomes of 264 probands, and their parents, and confirmed 329 de novo mutations. A likelihood analysis showed a significant excess of de novo mutations in the ∼4,000 genes that are the most intolerant to functional genetic variation in the human population (P = 2.9 × 10(-3)). Among these are GABRB3, with de novo mutations in four patients, and ALG13, with the same de novo mutation in two patients; both genes show clear statistical evidence of association with epileptic encephalopathy. Given the relevant site-specific mutation rates, the probabilities of these outcomes occurring by chance are P = 4.1 × 10(-10) and P = 7.8 × 10(-12), respectively. Other genes with de novo mutations in this cohort include CACNA1A, CHD2, FLNA, GABRA1, GRIN1, GRIN2B, HNRNPU, IQSEC2, MTOR and NEDD4L. Finally, we show that the de novo mutations observed are enriched in specific gene sets including genes regulated by the fragile X protein (P < 10(-8)), as has been reported previously for autism spectrum disorders.

The ideal proof-of-principle study design provides a strong efficacy signal over the shortest duration, while exposing the fewest patients possible. Data from a large database (Pfizer Inc) which studied add-on pregabalin for the treatment of partial seizures was used to model how duration of baseline, post-randomization treatment period, and number of subjects impact the likelihood of an interpretable efficacy signal. Data from four double-blind, randomized, placebo-controlled, phase III studies that had at least one 600mg/day treatment arm were combined. The common 6-week baseline period was divided into weekly intervals, as was the 12-week post-randomization period. Two methods of analysis were used: logistic regression performed on 50% responder rate and the Hodges-Lehmann estimate on percentage reduction from baseline seizure rate. A simulation-based re-sampling approach was used to determine sufficient sample size. Four weeks of baseline with 3 weeks of treatment were determined to be clinically and statistically sufficient. A reasonable sample size was estimated to be 40-50 patients per group, if a highly efficacious drug was used. These modeling results indicate that the efficacy of an antiepileptic drug can be demonstrated in a relatively short period of time with a reasonable sample size.

PURPOSE: To assess the effects of ICA-105665, an agonist of neuronal Kv7 potassium channels, on epileptiform EEG discharges, evoked by intermittent photic stimulation (IPS), the so-called photoparoxysmal responses (PPRs) in patients with epilepsy. METHODS: Male and female patients aged 18-60 years with reproducible PPRs were eligible for enrollment. The study was conducted as a single-blind, single-dose, multiple-cohort study. Four patients were enrolled in each of the first three cohorts. Six patients were enrolled in the fourth cohort and one patient was enrolled in the fifth cohort. PPR responses to 14 IPS frequencies (steps) were used to determine the standard photosensitivity range (SPR) following placebo on day 1 and ICA-105665 on day 2. The SPR was quantified for three eye conditions (eyes closing, eyes closed, and eyes open), and the most sensitive condition was used for assessment of efficacy. A partial response was defined as a reduction in the SPR of at least three units at three separate time points following ICA-105665 compared to the same time points following placebo with no time points with more than three units of increase. Complete suppression was defined by no PPRs in any eye condition at one or more time points. KEY FINDINGS: Six individual patients participated in the first three cohorts (100, 200, and 400 mg). Six patients participated in the fourth cohort (500 mg), and one patient participated in the fifth cohort (600 mg). Decreases in SPR occurred in one patient at 100 mg, two patients receiving 400 mg ICA-105665 (complete abolishment of SPR occurred in one patient at 400 mg), and in four of six patients receiving 500 mg. The most common adverse events (AEs) were those related to the nervous system, and dizziness appeared to be the first emerging AE. The single patient in the 600 mg cohort developed a brief generalized seizure within 1 h of dosing, leading to the discontinuation of additional patients at this dose, per the predefined protocol stopping rules. SIGNIFICANCE: ICA-105665 reduced the SPR in patients at single doses of 100 (one of four), 400 (two of four), and 500 mg (four of six). This is the first assessment of the effects of activation of Kv7 potassium channels in the photosensitivity proof of concept model. The reduction of SPR in this patient population provides evidence of central nervous system (CNS) penetration by ICA-105665, and preliminary evidence that engagement with neuronal Kv7 potassium channels has antiseizure effects.

A working group was created to address clinical "gaps to care" as well as opportunities for development of new treatment approaches for epilepsy. The working group primarily comprised clinicians, trialists, and pharmacologists. The group identified a need for better animal models for both efficacy and tolerability, and noted that animal models for potential disease-modifying or antiepileptogenic effect should mirror conditions in human trials. For antiseizure drugs (ASDs), current animal models have not been validated with respect to their relationship to efficacy in common epilepsy syndromes. The group performed an "expert opinion" survey of perceived efficacy of the available ASDs, and identified a specific unmet need for ASDs to treat tonic-atonic and myoclonic seizures. No correlation has as yet been demonstrated between animal models of tolerability and adverse effects (AEs), versus tolerability in humans. There is a clear opportunity for improved therapies in relation to dose-related AEs. The group identified common and rare epilepsy syndromes that could represent opportunities for clinical trials. They identified opportunities for antiepileptogenic (AEG) therapies in both adults and children, acknowledging that the presence of a biomarker would substantially improve the chances of a successful trial. However, the group acknowledged that disease-modifying therapies (given after the first seizure or after the development of epilepsy) would be easier to study than AEG therapies.

OBJECTIVE: Preapproval randomized controlled trials of antiepileptic drugs provide data in limited patient groups. We assessed the side effect and seizure reduction profile of tiagabine (TGB) in typical clinical practice. METHODS: Investigators recorded adverse effect (AE), seizure, and assessment-of-benefit data prospectively in sequential patients treated open label with TGB. RESULTS: Two hundred ninety-two patients (39 children) were enrolled to be treated long term with TGB. Seizure types were focal-onset (86%), generalized-onset (12%), both focal- and generalized-onset (0.3%), and multiple associated with Lennox-Gastaut Syndrome (2%). Two hundred thirty-one received at least one dose of TGB (median=28mg/day) and had follow-up seizure or AE data reported. Common AEs were fatigue, dizziness, psychomotor slowing, ataxia, gastrointestinal upset, weight change, insomnia, and "others" (mostly behavioral). Serious AEs occurred in 19 patients: behavioral effects (n=12), status epilepticus (n=3), others (n=3), and sudden unexplained death (n=1). No patients experienced suicidal ideation/behavior, rash, nephrolithiasis, or organ failure. Seizure outcomes were seizure freedom (5%), >/=75% reduction (12%), >/=50% reduction (23%), and increased number of seizures (17%), or new seizure type (1%). CONCLUSIONS: Behavioral AEs occurred in a larger proportion of patients compared to those reported in TGB preapproval randomized controlled trials. A moderate percentage of patients had a meaningful reduction in seizure frequency. In clinical practice, TGB remains a useful antiepileptic drug.