A phase 2, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of soticlestat as adjunctive therapy in pediatric patients with Dravet syndrome or Lennox-Gastaut syndrome (ELEKTRA).

Raising the bar: Fenfluramine sets new treatment standards for Dravet syndrome

ObjectiveTo evaluate the safety, tolerability, and pharmacokinetics of soticlestat, a first-in-class cholesterol 24-hydroxylase inhibitor, in adults with developmental and/or epileptic encephalopathies (DEE). MethodsThe study comprised a 30-day, randomized, double-blind, placebo-controlled phase (Part A), followed by a 55-day open-label phase (Part B) (ClinicalTrials.gov ID: NCT03166215) . In Part A, patients with DEE and at least one bilateral motor seizure during the 4-week prospective baseline period were randomized 4:1 to receive soticlestat or placebo, in addition to their usual antiseizure medication. In Part B, all patients received open-label soticlestat. Soticlestat doses were titrated according to tolerability to a maximum of 300 mg twice daily (BID). Safety evaluations included the incidence of treatment-emergent adverse events (TEAEs). Plasma soticlestat concentrations were measured at various times for determination of multiple-dose pharmacokinetics and 24S-hydroxycholesterol (24HC). Efficacy was assessed by evaluation of changes in seizure frequency from baseline. ResultsEighteen patients (median age, 28.5 years) were enrolled and randomized, and 14 (78 %) completed the study. In Part A, TEAEs occurred in 71.4 % of soticlestat-treated patients and 100 % of placebo-treated patients. In Part B, the overall incidence of TEAEs was 68.8 %. In Part A, TEAEs that occurred in more than one patient in the soticlestat group were dysarthria (n = 3, 21.4 %), lethargy (n = 2, 14.3 %), upper respiratory tract infection (n = 2, 14.3 %), fatigue (n = 2, 14.3 %), and headache (n = 2, 14.3 %). Four patients discontinued treatment because of TEAEs, of whom two reported drug-related seizure clusters as serious TEAEs. There were no deaths. Pharmacokinetic analysis showed dose-dependent increases in systemic exposure and peak plasma soticlestat concentrations. At the end of Part B, the overall mean percent change from baseline in plasma 24HC was −80.97 %. Changes from baseline in median seizure frequency were +16.71 % and +22.16 % in the soticlestat and placebo groups, respectively, in Part A, and −36.38 % in all participants in Part B. ConclusionSoticlestat was well tolerated at doses of up to 300 mg BID and was associated with a reduction in median seizure frequency over the study duration. Further studies are warranted to assess the possible efficacy of soticlestat as adjunctive therapy in patients with DEEs such as Dravet syndrome and Lennox–Gastaut syndrome.

IntroductionFenfluramine (FFA) is an amphetamine derivative that promotes the release and blocks the neuronal reuptake of serotonin. Initially introduced as an appetite suppressant, FFA also showed antiseizure properties. This systematic review aimed to assess the efficacy and safety of FFA for the treatment of seizures in patients with epilepsy.MethodsWe systematically searched (in week 3 of June 2022) MEDLINE, the Cochrane Central Register of Controlled Trials, and the US National Institutes of Health Clinical Trials Registry. Randomized, double- or single-blinded, placebo-controlled studies of FFA in patients with epilepsy and uncontrolled seizures were identified. Efficacy outcomes included the proportions of patients with ≥ 50% and 100% reductions in baseline seizure frequency during the treatment period. Tolerability outcomes included the proportions of patients who withdrew from treatment for any reason and suffered adverse events (AEs). The risk of bias in the included studies was assessed according to the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions. The risk ratio (RR) along with the 95% confidence interval (CI) were estimated for each outcome.ResultsThree trials were identified and a total of 469 Dravet syndrome (DS) and Lennox–Gastaut syndrome (LGS) subjects were randomized. All three trials were judged to be at low risk of biases. In patients with DS, the RRs for ≥ 50% and 100% reductions in convulsive seizure frequency for the FFA group compared to placebo were 5.61 (95% CI 2.73–11.54) and 4.71 (95% CI 0.57–39.30), respectively. In patients with LGS, the corresponding RRs for ≥ 50% and 100% reductions in drop seizure frequency were 2.58 (95% CI 1.33–5.02) and 0.50 (95% CI 0.031–7.81), respectively. The drug was withdrawn for any reason in 10.1% and 5.8% of patients receiving FFA and placebo, respectively (RR 1.79, 95% CI 0.89–3.59). Treatment discontinuation due to AEs occurred in 5.4% and 1.2% of FFA- and placebo-treated patients, respectively (RR 3.63, 95% CI 0.93–14.16). Decreased appetite, diarrhoea, fatigue, and weight loss were AEs associated with FFA treatment.ConclusionFenfluramine reduces the frequency of seizures in patients with DS and LGS. Decreased appetite, diarrhoea, fatigue, and weight loss are non-cardiovascular AEs associated with FFA.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40120-023-00452-1.

<h3>Objective:</h3> To develop a post hoc analysis of soticlestat treatment efficacy by seizure type in patients with Dravet syndrome (DS) or Lennox–Gastaut syndrome (LGS) in ELEKTRA (NCT03650452), a phase 2, randomized, placebo-controlled study of adjunctive soticlestat (≤300 mg BID, weight-adjusted) in children aged 2–17 years with DS demonstrating ≥3 convulsive seizures/28 days, or with LGS demonstrating ≥4 drop seizures/28 days at baseline. <h3>Background:</h3> DS and LGS involve developmental delay and frequent epileptic activity. The published ELEKTRA study investigated efficacy and safety of soticlestat, a cholesterol 24-hydroxylase inhibitor, in children with DS or LGS. Primary endpoint was change in convulsive (DS) and drop (LGS) seizure frequencies. <h3>Design/Methods:</h3> Post hoc efficacy analyses determined percent change in seizure frequency from baseline, by seizure type. Patients’ caregivers recorded seizure number and type throughout the baseline and full (20-week) treatment periods, including generalized tonic–clonic, focal to bilateral tonic–clonic, focal with motor signs and atonic seizures. <h3>Results:</h3> Of 141 enrolled patients, 126 (89%) completed ELEKTRA. The modified intent-to-treat population received ≥1 doses of study drug and had ≥1 efficacy assessments (DS, n=51; LGS, n=88). Median seizure frequency changes from baseline in patients with DS receiving soticlestat (placebo): generalized tonic–clonic seizures, −27.2% [n=14] (19.5%, n=21); focal to bilateral tonic–clonic seizures, −73.9% [n=9] (8.4%, n=4). Median seizure frequency changes from baseline in patients with LGS receiving soticlestat (placebo): generalized tonic–clonic seizures, −33.4% [n=17] (−20.0%, n=11); focal seizures with motor signs, −64.3% [n=10] (−21.1%, n=7); atonic seizures, −33.9% [n=16] (−17.9%; n=13); focal to bilateral tonic–clonic seizures, −41.3% [n=6] (none observed). <h3>Conclusions:</h3> Reduced median frequency of specific seizure types was observed in patients receiving soticlestat as adjunctive therapy. Investigation of soticlestat adjunctive therapy for these seizure types in other epilepsies is warranted (phase 3 studies ongoing for DS and LGS). Study funded by Takeda Pharmaceutical Company Limited. <b>Disclosure:</b> Dr. Pathi Jagannatham has received personal compensation for serving as an employee of Takeda Pharmaceuticals. Dr. Pathi Jagannatham has received personal compensation for serving as an employee of GlaxoSmithKline. Dr. Pathi Jagannatham has stock in Takeda Pharmaceuticals. Dr. Pathi Jagannatham has stock in GlaxoSmithKline. Dr. Dlugos has received research support from NIH. The institution of Dr. Dlugos has received research support from The Epilepsy Study Consortium. Yasir Khan has nothing to disclose. Dr. Hsiao has received personal compensation for serving as an employee of Takeda Pharmaceutical Company. Dr. Hsiao has stock in Takeda Pharmaceutical Company. Dr. Benitez has received personal compensation for serving as an employee of Takeda . Mahnaz Asgharnejad, PharmD has received personal compensation for serving as an employee of Takeda Pharmaceuticals. Mahnaz Asgharnejad, PharmD has stock in GlaxoSmithKline. Mahnaz Asgharnejad, PharmD has stock in Takeda Pharmaceuticals.

[Box: see text]

Ketogenic diet therapies have proven efficacy for refractory epilepsy. There are many reports of their use in the genetic developmental and epileptic encephalopathies; however, little attention has been paid as to whether the diet is also effective in individuals with an acquired structural aetiology. We observed remarkable efficacy of the diet in two patients with hypoxic-ischaemic encephalopathy. We then analysed our cases with refractory structural epilepsies of acquired origin to characterize their response to the ketogenic diet. The classical ketogenic diet was implemented with dietary ratios of 3:1 to 4.4:1. Seizure frequency at 1month, 3months, 6months, 1year, and 2years was ascertained. A responder was defined as greater than 50% seizure reduction compared to baseline. Seven of the nine patients were responders at 3months. Somewhat surprisingly we found that the ketogenic diet was effective in patients with a developmental and epileptic encephalopathy due to an acquired structural aetiology. This cohort may not be routinely considered for the ketogenic diet because of their structural and acquired, rather than genetic, basis. The ketogenic diet should be considered early in the management of patients with acquired structural encephalopathies as it can improve seizure control with the potential to improve developmental outcome. The ketogenic diet was effective in children with epilepsy associated with an acquired structural aetiology.

PurposeThis retrospective chart review study (GWEP20052) evaluated plant-derived highly purified cannabidiol (CBD; Epidyolex®; 100 mg/mL oral solution) use without clobazam as add-on therapy in patients aged ≥2 years with Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) enrolled in a European Early Access Program. MethodsData were extracted from patient charts covering a period starting 3 months before CBD treatment and concluding after 12 months of CBD treatment, or sooner if a patient discontinued CBD or started clobazam. ResultsOf 114 enrolled patients, data were available for 107 (92 LGS, 15 DS) who received CBD without clobazam for ≥3 months. Mean age: 14.5 (LGS) and 10.5 (DS) years; female: 44% (LGS) and 67% (DS). Mean time-averaged CBD dose: 13.54 (LGS) and 11.56 (DS) mg/kg/day. Median change from baseline in seizure frequency per 28 days over 3-month intervals varied from −6.2% to −20.9% for LGS and 0% to −16.7% for DS. Achievement of ≥50% reduction in drop (LGS) or convulsive (DS) seizures at 3 and 12 months: LGS, 19% (n = 69) and 30% (n = 53); DS, 21% (n = 14) and 13% (n = 8). Retention on CBD without clobazam (enrolled set): 94%, 80%, 69%, and 63% at 3, 6, 9, and 12 months. Adverse event (AE) incidence was 31%, most commonly somnolence, seizure, diarrhea, and decreased appetite. Two patients discontinued CBD owing to AEs, and four patients with LGS experienced elevated liver enzymes. ConclusionResults support favorable effectiveness and retention of CBD without concomitant clobazam for up to 12 months in clinical practice.

ObjectiveFenfluramine has been shown to provide clinically meaningful and statistically significant reductions in convulsive seizure frequency in children and adolescents (aged 2‐18 years) with Dravet syndrome in two randomized, placebo‐controlled clinical trials. The objective of this analysis was to assess longer‐term safety and efficacy of fenfluramine in patients who completed one of the double‐blind studies and entered an open‐label extension (OLE) study.MethodsPatients enrolling in the OLE study initiated fenfluramine at 0.2 mg/kg/d regardless of their treatment assignment in the double‐blind study. After 4 weeks, the fenfluramine dose could be titrated based on efficacy and tolerability to maximum of 0.7 mg/kg/d (absolute maximum 27 mg/d) or maximum of 0.4 mg/kg/d (absolute maximum 17 mg/d) in patients receiving concomitant stiripentol. The number and type of seizures were recorded daily in an electronic diary, and safety, including echocardiography, was assessed at Months 1, 2, and 3, and at 3‐month intervals thereafter.ResultsA total of 232 patients were enrolled as of March 13, 2018. During this analysis period, patients were treated for a median 256 days (range = 46‐634 days). Over the entire OLE analysis period, the median decrease in convulsive seizure frequency compared to baseline in the double‐blind studies was −66.8% (range = −100% to 234.9%; P < .001). The median reduction in seizure frequency was similar in patients <6 (−75.7%) and ≥6 years old (−64.7%). The most commonly reported adverse events included pyrexia (21.6%), nasopharyngitis (19.4%), and decreased appetite (−15.9%). No valvular heart disease (VHD) or pulmonary arterial hypertension (PAH) was observed.SignificanceStudy results demonstrate that fenfluramine provides clinically meaningful (≥50%) seizure frequency reduction over an extended period in patients with Dravet syndrome. No patient developed VHD or PAH, and fenfluramine was generally well tolerated.

Fenfluramine hydrochloride for the treatment of seizures in Dravet syndrome: a randomised, double-blind, placebo-controlled trial

The drug-resistant epilepsy associated with Lennox-Gastaut syndrome (LGS) has a long-term effect on patients and is difficult to treat with conventional pharmacological and nonpharmacological therapies. Our objective is to demonstrate that adjunctive vagus nerve stimulation (VNS) can help manage the seizures associated with LGS. CORE-VNS (NCT03529045) is a prospective, multicenter, multinational observational study to collect data on seizure and nonseizure outcomes following treatment with VNS. Participants were identified as having a documented LGS diagnosis and received initial VNS implants. Baseline seizure frequency data and patient-reported outcome measures were collected at 3, 6, 12, 24, and 36 months. This interim analysis compared baseline data to VNS therapy outcomes at 24 months, and the results are presented here. Sixty participants in the CORE-VNS study had a diagnosis of LGS and received an initial implant of VNS. The population was geographically diverse: 31.7% European, 26.7% from the Americas, and 26.7% from the Western Pacific. The median age at implant was 11.8 years (range = 2.2-47.6), and only 26.7% of those diagnosed with LGS were >18 years of age. Most (70%) of the participants had severe cognitive impairment. The LGS participants failed a median of 6 antiseizure medications, and 83.3% had not undergone epilepsy surgery. The LGS responder rate (≥50% reduction in seizure frequency) at 24 months for focal and generalized seizures was 66.7% and 47.4%, respectively. Some participants (20%, 12/60) experienced a ≥80% reduction in total seizure frequency. VNS was well tolerated, with only 15% (9/60) reporting at least one treatment-emergent adverse event, primarily cough, dysphonia, and oropharyngeal pain. LGS participants who received adjunctive VNS therapy to manage seizures were predominantly severely cognitively impaired children. Reductions in seizure frequency, including those with drops, and the sustained nature of the response support VNS as a promising therapy in LGS.

Adjunctive use of cenobamate for pediatric refractory focal-onset epilepsy: A single-center retrospective study

To evaluate the potential impact of concomitant clobazam (CLB) use on the efficacy of cannabidiol (CBD) treatment in patients with Dravet syndrome and Lennox-Gastaut syndrome using meta-analytical techniques. We searched for randomized, placebo-controlled, single- or double-blinded trials. The proportion of patients who achieved ≥50% reduction from baseline in seizure frequency during the treatment period was assessed according to CLB status. Risk ratios (RRs) with 95% confidence intervals (CIs) were estimated. Four trials were included and enrolled 714 participants, 429 for the add-on CBD group and 285 for the add-on placebo group. Among CBD-treated patients, 240 (55.9%) were taking concomitant CLB (CLB-On) and 189 (44.1%) were not taking concomitant CLB (CLB-Off); in placebo-treated patients, 158 (55.4%) were CLB-On and 127 (44.6%) CLB-Off. The percentages of patients who had at least 50% reduction in seizure frequency during the treatment period were 29.1% in the CBD arm and 15.7% in the placebo group among CLB-Off patients (RR = 1.80, 95% CI = 1.12-2.90, P=.015). Among CBL-On patients, the ≥50% reduction in seizure frequency was found in 52.9% and 27.8% in the CBD and placebo groups, respectively (RR = 1.85, 95% CI = 1.40-2.44, P<.001). CBD was associated with a higher rate of seizure response in comparison to placebo when added to the existing antiepileptic regimen both in patients taking and in those not taking concomitant CLB. The lack of randomization for CLB status and the limited sample size need to be considered in the interpretation of the findings.

To evaluate the long-term efficacy, safety, and tolerability of adjunctive perampanel for the treatment of patients with refractory focal-onset seizures (FOS), with or without focal to bilateral tonic-clonic seizures (FBTCS), from the Asia-Pacific region. Study 335 (NCT01618695) was a randomized, double-blind, placebo-controlled, Phase III study. Patients aged ≥12 years with refractory FOS who completed the Core Study could enter an open-label extension (OLEx) Phase (6-week Conversion and ≥46-week Maintenance Period). Endpoints included median percent reduction in seizure frequency per 28 days, 50% responder and seizure-freedom rates, and treatment-emergent adverse events (TEAEs). The Intent-to-Treat Analysis Set included 704 patients (529 received perampanel and 175 received placebo during the Core Study; all patients received perampanel during OLEx). The median percent reduction in seizure frequency and 50% responder rates in patients who received perampanel during the Core Study were maintained throughout the OLEx Phase (Week 64-75: 55.9% and 54.3%, respectively). Seizure freedom for ≥12 consecutive months at any time during perampanel treatment was achieved by 4.1% of patients with FOS and 14.2% of patients with FBTCS. Among patients treated with perampanel 4 mg/day (n = 83), median reduction in seizure frequency was lower in those who received concomitant enzyme-inducing anti-seizure medications (EIASMs) than those who received non-EIASMs. The most common TEAE was dizziness (n = 318; 46.8%); 141 (20.8%) patients had TEAEs that led to study/drug withdrawal. Overall, long-term seizure control was achieved with adjunctive perampanel in patients with refractory FOS, with or without FBTCS, in an Asia-Pacific population.

Lennox-Gastaut syndrome (LGS) is a severe developmental epileptic encephalopathy, and available interventions fail to control seizures in most patients. Cannabidiol (CBD) is a major chemical of marijuana, which has anti-seizure properties and different mechanisms of action compared with other approved antiepileptic drugs (AEDs). The aim was to evaluate the efficacy and safety of CBD as adjunctive treatment for seizures in patients with LGS using meta-analytical techniques. Randomized, placebo-controlled, single- or double-blinded trials were identified. Main outcomes included the ≥ 50% reduction in baseline drop and non-drop seizure frequency, and the incidence of treatment withdrawal and adverse events (AEs). Risk ratios (RRs) with 95% confidence intervals (CIs) were estimated through the inverse variance method. Two trials were included involving 396 participants. Patients presenting ≥ 50% reduction in drop seizure frequency during the treatment were 40.0% with CBD and 19.3% with placebo [RR 2.12 (95% CI 1.48-3.03); p < 0.001]. The rate of non-drop seizure frequency was reduced by 50% or more in 49.4% of patients in the CBD and 30.4% in the placebo arms [RR 1.62 (95% CI 1.09-2.43); p = 0.018]. The RR for CBD withdrawal was 4.93 (95% CI 1.50-16.22; p = 0.009). The RR to develop any AE during CBD treatment was 1.24 (95% CI 1.11-1.38; p < 0.001). AEs significantly associated with CBD were somnolence, decreased appetite, diarrhea and increased serum aminotransferases. Adjunctive CBD resulted in a greater reduction in seizure frequency and a higher rate of AEs than placebo in patients with LGS presenting seizures uncontrolled by concomitant AEDs.

The Phase 3 Study 338 (NCT02834793) assessed long-term clinical outcomes of adjunctive perampanel in patients ≥2 years of age with uncontrolled seizures associated with Lennox-Gastaut syndrome (LGS). Eligible patients were diagnosed with LGS and receiving one to four concomitant antiseizure medications with an average of two or more drop seizures/week during baseline. The study comprised an 18-week double-blind, randomized, placebo-controlled Core Study and ≥52-week open-label Extension. The primary endpoint was median percent change in drop seizure frequency per 28 days during the Core Study. Key secondary endpoints included responder rates, seizure-freedom rates, and safety outcomes. Post hoc analyses were performed encompassing a broader range of drop seizures or all countable motor seizures. Seventy patients were randomized into the Core Study (perampanel, n = 34; placebo, n = 36), and 58 entered the Extension. In the Core Study, numerically greater median percent reductions in drop seizure frequency were observed with perampanel (23.1%) vs placebo (4.5%) using prespecified assessments (p = .107), whereas significantly greater reductions were detected using the broader definition (48.6% vs -.7%, respectively, p = .001) or all countable motor seizures (44.0% vs -.6%, respectively, p = .017). The 50% responder rate for drop seizures was higher with perampanel vs placebo using modern definitions. Reductions in seizure frequency with perampanel were maintained over 52 weeks. Treatment-emergent adverse events occurred in 85.3% of perampanel-treated patients (somnolence [23.5%] was the most frequent) and 72.2% of placebo-treated patients. This study had a reduced sample size and was underpowered. Although the difference in reductions in drop seizure frequency between treatments was not statistically significant by prespecified assessments, adjunctive perampanel demonstrated sustained efficacy in reducing drop seizures associated with LGS for ≤71 weeks using modern definitions. No new safety signals emerged. These observations suggest the long-term efficacy and safety of perampanel in the LGS population.