Epilepsy Research Findings: June 2019

This month’s round-up of epilepsy news features an announcement about a new antiepileptic rescue medication, NAYZILAM®. This therapy is the first FDA-approved nasal treatment option for people with epilepsy who experience episodes of frequent seizure activity.

We also highlight many research advances, from the discovery of a compound found in fruit and honey which can inhibit seizures to the development of a new drug to treat Dravet syndrome. Research in the cannabidiol (CBD) space has also advanced, with the creation of a synthetic form of CBD which may be easier to purify and does not need to be cultivated from hemp plants.

In more sobering news, reports over the past month show that one-third of epilepsy cases go without appropriate treatment for up to three years following diagnosis. In addition, people with psychogenic nonepileptic seizures (PNES) as well as epileptic seizures may be at a higher risk for sudden unexpected death in epilepsy (SUDEP)during the years immediately following diagnosis with PNES.

Summaries of all highlighted studies follow below. I’ve organized the findings into three categories: Treatment Advances, Research Discoveries, and Also Notable.

Treatment Advances

FDA Approves NAYZILAM® Nasal Spray to Treat Intermittent, Stereotypic Episodes of Frequent Seizure Activity in People Living with Epilepsy in the US
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The FDA has approved a New Drug Application for UCB’s newest antiepileptic drug NAYZILAM® (midazolam) nasal spray. This therapy is a benzodiazepine indicated for the acute treatment of intermittent, stereotypic episodes of frequent seizure activity (i.e., seizure clusters, acute repetitive seizures) distinct from a patient’s usual seizure pattern in individuals with epilepsy who are 12 years of age and older.

Study Advances More Effective Laser Ablation and Standard Epilepsy Surgery 
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In the largest study of its kind to date, researchers across 11 centers analyzed data on a relatively new minimally invasive alternative surgery for epilepsy. These researchers discovered changes that could make the procedure more effective in both laser ablation and standard surgery.

Research Discoveries

Brain Network Activity can Improve in Epilepsy Patients after Surgery
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Successful epilepsy surgery can improve brain connectivity similar to patterns seen in people without epilepsy, according to a new study published in the journal Neurosurgery. The study of 15 people with temporal lobe epilepsy is the first to show improvements in brain networks after surgery compared to a group of healthy subjects.

New Drug Could Help Treat Neonatal Seizures
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A new drug that inhibits neonatal seizures in rodent models could open new avenues for epilepsy treatment in human newborns. Researchers have found that gluconate—a small organic compound found in fruit and honey—acts as an anticonvulsant, inhibiting seizures by targeting the activity of channels that control the flow of chloride ions in and out of neonatal neurons.

Research Looks to Halt Stress-Induced Seizures Following Brain Injury
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The likelihood of developing epilepsy increases significantly with a traumatic brain injury. Stress and anxiety increase that likelihood even more dramatically. Researchers have been able to demonstrate that an injured brain responds differently to stress hormones than a healthy brain. The research team showed abnormal electrical activity in the brain tied to these stress-induced seizures and, most importantly, found a way to stop this activity from occurring.

Synthetic Version of Cannabidiol (CBD) Treats Seizures in Rats
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A synthetic, non-intoxicating analogue of CBD was found to be effective for treating seizures in rats. Researchers note the synthetic CBD alternative is easier to purify than a plant extract, eliminates the need to use agricultural land for hemp cultivation, and could avoid legal complications associated with cannabis-related products.

AZD7325 Has Seizure-Protective Effect in Mouse Model of Dravet Syndrome, Study Says
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Treatment with AZD7325, a compound that stimulates an inhibitory receptor in the brain, has a seizure-protective effect in a mouse model of Dravet syndrome. This treatment significantly increased the temperature threshold animals could withstand without experiencing any seizures during a hyperthermia-induced seizure test.

Children’s Brains Reorganize after Epilepsy Surgery to Retain Visual Perception
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Children can keep their full ability to process and understand visual information after brain surgery for severe epilepsy, according to a study funded by the National Eye Institute, part of the National Institutes of Health. This new report from a study of children who underwent epilepsy surgery and suggests that the lasting effects on visual perception can be minimal, even among children who lost tissue in the brain’s visual centers.

One-Third of Epilepsy Cases Go Untreated up to 3 Years After Diagnosis
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A small yet substantial subset of patients with newly diagnosed epilepsy go without appropriate treatment approximately 3 years after diagnosis. This gap in treatment may be increasing the risk for medical events and hospitalization in these patients.

Study Suggests ‘High Risk Period’ for SUDEP for People with Psychogenic Nonepileptic Seizures in Addition to Epileptic Seizures 
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Findings of a recently published study suggest that patients with comorbid epileptic seizures (ES) and Psychogenic Nonepileptic Seizures (PNES) can die from SUDEP and that there may be a high?risk period after the diagnosis of PNES is made. The authors state such patients should be closely monitored and provided with coordinated care of both their epilepsy and psychiatric disorder(s).

Also Notable

Fralin Biomedical Research Institute Neuroscientist Awarded Grant to Study Epilepsy
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Featuring CURE Grantee Dr. Sharon Swanger

Dr. Sharon Swanger of the Fralin Biomedical Research Institute was recently awarded a $1.7 million grant through the National Institute of Neurological Disorders and Stroke to study the role of glutamate receptors in the thalamus – an area of the brain involved in seizure generation. “If we can figure out how each [receptor] subtype functions and modulate select subtypes, then maybe we can target therapies to the circuit where the disease originated while leaving healthy circuits intact,” said Dr. Swanger.

Tool Helps GPs Predict Risk of Seizures in Pregnancy
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Doctors, midwives, and others can use a new risk calculator to identify those pregnant women at high-risk of seizures and to plan early referral for specialist input. The specialist could determine the need for close monitoring in pregnancy, labor, and after birth, and assess antiepileptic drug management, according to new research in PLOS Medicine. The study authors added that the model’s performance is unlikely to vary with the antiepilepsy drug dose management strategy – and that it could save maternal and infant lives.

Development of Epilepsy Prediction Device to Improve Independence for People with Epilepsy
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The University of Sydney’s Faculty of Engineering and Information Technologies is developing a system, NeuroSyd, which aims at real-time monitoring and processing of brain-signals while driving in a group of people living with epilepsy. NeuroSyd will be developed to deliver an early warning of the likelihood of an epileptic seizure.

Pfizer’s Lyrica at Doses 5mg and 10mg Fails Phase 3 Trial in Epilepsy
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Pfizer’s Lyrica has failed to meet its primary endpoint in a phase 3 trial in primary generalized tonic-clonic (PGTC) seizures. The study evaluated two doses of the drug – 5 mg and 10 mg – over a period of 12 weeks. Treatment with the drug did not result in a statistically significant reduction in seizure frequency versus placebo. Another phase 3 trial in May 2018 was successful, showing that a 14 mg dose of Lyrica resulted in a statistically significant reduction in seizure frequency versus placebo.

A dropper adding liquid to an extract in a bottle with cannibals leafs in the background.

Synthetic Version of CBD Treats Seizures in Rats

A synthetic, non-intoxicating analogue of cannabidiol (CBD) is effective in treating seizures in rats, according to research by chemists at the University of California, Davis.

The synthetic CBD alternative is easier to purify than a plant extract, eliminates the need to use agricultural land for hemp cultivation, and could avoid legal complications with cannabis-related products. The work was recently published in the journal Scientific Reports.

“It’s a much safer drug than CBD, with no abuse potential and doesn’t require the cultivation of hemp,” said Mark Mascal, professor in the UC Davis Department of Chemistry. Mascal’s laboratory at UC Davis carried out the work in collaboration with researchers at the University of Reading, U.K.

The researchers tested synthetic H2CBD against herbal CBD in rats with induced seizures. H2CBD and CBD were found to be equally effective for the reduction of both the frequency and severity of seizures.

Mascal is working with colleagues at the UC Davis School of Medicine to carry out more studies in animals with a goal of moving into clinical trials soon. UC Davis has applied for a provisional patent on antiseizure use of H2CBD and its analogues, and Mascal has founded a company, Syncanica, to continue development.

Epilepsy Research Findings: May 2019

In this month’s research news, treatments, genetic analysis, and preclinical work offer hope to those impacted by hard-to-treat or difficult-to-diagnose forms of epilepsy.

Exciting treatment developments include a positive Phase 3 clinical trial outcomefor the cannabidiol-based drug EPIDIOLEX® for the treatment of seizures associated with tuberous sclerosis complex. In addition, an improved treatment regimen targeting the severe, prolonged seizures that make up status epilepticus has been created.

In promising genetics news, a report from CURE’s own Epilepsy Genetics Initiativeunderscores the value of continued reanalysis of genetic information from people with epilepsy to increase their chances of obtaining a genetic diagnosis for their epilepsy.

Additionally, important preclinical work led by CURE Grantees Dr. Chris Dulla and Dr. Janice Naegele uncovers a potential drug to treat post-traumatic epilepsy and a way to restore the balance of brain activity and reduce seizures in temporal lobe epilepsy, respectively.

Summaries of all highlighted studies follow below. I’ve organized the findings into four categories: Treatment Advances, Diagnostic Advances, Research Discoveries, and Also Notable.

Treatment Advances

GW Pharmaceuticals Reports Reduction in Seizure Frequency for EPIDIOLEX® (cannabidiol) Oral Solution in Patients with Seizures Associated With Tuberous Sclerosis Complex
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GW Pharmaceuticals and Greenwich Biosciences announced positive top-line results of a Phase 3 clinical trial of EPIDIOLEX® (cannabidiol or CBD) in the treatment of seizures associated with Tuberous Sclerosis Complex (TSC). TSC is a rare and severe form of childhood-onset epilepsy. In this trial, EPIDIOLEX met its primary endpoint, which was a reduction in seizure frequency in the group given EPIDIOLEX compared to the placebo group.

Breakthrough for Children with Serious Epileptic Seizures
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A new treatment regimen of administering levetiracetam and phenytoin one after the other has given emergency medicine doctors a better way to treat severe, prolonged epileptic seizures in children. These treatment modifications will lower the chances of intubation and intensive care, as well as increase the chances of children recovering more quickly.

Diagnostic Advances

The Epilepsy Genetics Initiative: Systematic Reanalysis of Diagnostic Exomes Increases Yield
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Featuring CURE’s Epilepsy Genetics Initiative

Results from CURE’s Epilepsy Genetics Initiative (EGI) show that when the genetic information of a person with epilepsy is systematically reanalyzed, there is an increase in the return of a genetic diagnosis. Eight new diagnoses were made as a result of updated annotations or the discovery of novel epilepsy genes after the initial diagnostic analysis was performed. One novel epilepsy gene was discovered through dual interrogation of research and clinically generated whole-exome sequencing. According to this recently-published report, EGI’s contributions to gene discovery underscore the importance of data sharing and the value of collaborative enterprises.

Research Discoveries

Using a Drug that Mimics the Ketogenic Diet to Help Prevent Epilepsy after Traumatic Brain Injury
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Featuring the work of CURE Grantee Dr. Chris Dulla

Neuroscientists led by CURE Grantee Dr. Chris Dulla at Tufts University School of Medicine prevented the development of epileptic activity in mice after traumatic brain injury by using a drug that mimics the metabolic effects of the ketogenic diet.

Neural Stem Cell Transplantation May Reduce Abnormal Increases in New Cells in the Brains of Mice with Temporal Lobe Epilepsy
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Featuring the work of CURE Grantee Dr. Janice Naegele

According to a new, CURE-funded study featuring the work of grantee Dr. Janice Naegele, the transplantation of inhibitory cells into the brains of mice with temporal lobe epilepsy may reduce the abnormal growth of new neurons in an area of the brain called the hippocampus. This in turn could reduce brain hyperexcitability that leads to seizures.

Stimulating the Epileptic Brain Breaks Up Neural Networks to Prevent Seizures
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Responsive neurostimulation treats epilepsy by detecting seizures and intervening with a jolt of electric current. Over time, most patients find their seizures become fewer and further between. New evidence suggests responsive neurostimulation can remodel the brain to be less susceptible to seizures.

Scientists Discover Trigger Region for Absence Epileptic Seizures
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Scientists have discovered a neurological origin for absence seizures – a type of seizure characterized by very short periods of lost consciousness in which people appear to stare blankly at nothing. Using a mouse model of childhood epilepsy, a group of scientists has shown that absence epilepsy can be triggered by impaired communication between two brain regions: the cortex and the striatum.

Autism-Related Memory and Seizures Improved through Gene Repair in Adults
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Scientists have shown that correcting the protein deficiency caused by a genetic form of autism spectrum disorder in adult mice can improve behavioral and electrophysiological measures of both memory and seizure. The evidence suggests this is true even when the treatment is carried out well past what has traditionally been thought of as the critical window of early brain development.

Drug Used to Treat Multiple Sclerosis May Be Beneficial for Individuals with Epilepsy 
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A drug commonly used to treat multiple sclerosis may, after necessary modifications, one day be used to treat patients with epilepsy, according to research from the laboratory of Dr. Inna Slutsky.

Study Reveals How Glial Cells May Play Key Epilepsy Role
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A study provides potential new targets for treating epilepsy and novel fundamental insights into the relationship between neurons and their glial “helper” cells. This study reports finding a key sequence of molecular events in which the genetic mutation in a fruit fly model of epilepsy leaves neurons vulnerable to becoming hyper-activated by stress, leading to seizures.

Ketogenic Diet May Reduce Sudden Unexpected Deaths in Epilepsy, Mouse Study Suggests
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Sudden unexpected death in epilepsy (SUDEP) occurs more frequently during the early evening and is significantly prevented by prolonged use of the ketogenic diet, research in a mouse model of Dravet syndrome suggests. The reasons why this happens are unclear and should be examined in more depth by future studies, but these findings may be useful to understand why most SUDEP episodes happen at night and how certain diets can benefit people with epilepsy, especially those with Dravet syndrome, researchers say.

Attention, Behavioral Problems Common in New, Recent-Onset Juvenile Myoclonic Epilepsy
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Children with new recent-onset juvenile myoclonic epilepsy are more likely to have difficulty with executive, attention, and verbal faculties than their healthy peers and are also more likely to use a greater number of academic services, researchers found.

Also Notable

Zogenix Receives Refusal to File Letter from FDA for FINTEPLA® New Drug Application
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Zogenix announced that it received a Refusal to File letter from the FDA regarding its New Drug Application (NDA) for FINTEPLA® for the treatment of seizures associated with Dravet syndrome. Upon its preliminary review, the FDA determined that the NDA was not sufficiently complete to permit a substantive review.

Purified CBD Reduces Seizures in Rare Form of Childhood Epilepsy by Almost 50%, Study Finds

Highly purified cannabidiol (CBD) at a dose of 10mg/kg/day can reduce convulsive seizures in children with Dravet syndrome by almost 50%, a study published in Neurology has found.

Dravet syndrome is a rare, severe form of childhood epilepsy and current medicines are unable to provide complete seizure control.

The study investigated 199 patients with Dravet syndrome who were already taking a median of three anti-epileptic drugs. The patients, who had a mean age of 9 years, were randomized to receive either highly purified CBD at 20mg/kg/day (CBD20), highly purified CBD at 10mg/kg/day (CBD10) or placebo.

The researchers then examined the change in convulsive seizure frequency over a 14-week treatment period by comparing it to the 4 weeks before treatment.

They found that in the group taking CBD20, the number of convulsive seizures was reduced by 46%, while in the CBD10 group the number of seizures was reduced by 49%. In the placebo group, the number of seizures reduced by 27%.

“It’s exciting to be able to offer another alternative for children with this debilitating form of epilepsy, and their families,” said study author Ian Miller, a neurologist at Nicklaus Children’s Hospital in Florida.

“The children in this study had already tried an average of four epilepsy drugs with no success, and [when the study was conducted] were taking an average of three additional drugs, so to have this measure of success with cannabidiol is a major victory.”

GW Pharmaceuticals Reports Positive Phase 3 Pivotal Trial Results for EPIDIOLEX® (cannabidiol) Oral Solution in Patients with Seizures Associated With Tuberous Sclerosis Complex

GW Pharmaceuticals and its US subsidiary Greenwich Biosciences Inc. announced positive top-line results of a randomized, double-blind, placebo-controlled Phase 3 clinical trial of EPIDIOLEX® (cannabidiol or CBD) CV in the treatment of seizures associated with Tuberous Sclerosis Complex (TSC), a rare and severe form of childhood-onset epilepsy. In this trial, EPIDIOLEX met its primary endpoint, which was the reduction in seizure frequency compared to baseline of the Epidiolex 25 mg/kg/day dose group vs placebo (p=0.0009).

Results for both the 25 and 50 mg/kg/day dose groups were similar, with seizure reductions of 48.6% and 47.5% from baseline respectively, vs 26.5% for placebo (50 mg/kg/day vs placebo, p=0.0018). All key secondary endpoints were supportive of the effects on the primary endpoint. The safety profile observed is consistent with findings from previous studies, with no new safety risks identified.

“The positive outcome in this trial of EPIDIOLEX in patients with Tuberous Sclerosis Complex expands both our knowledge of this newly available medicine and its potential utility beyond the current indications,” stated Elizabeth Thiele, M.D., Ph.D., Director of the Herscot Center for Tuberous Sclerosis Complex at Massachusetts General Hospital, Professor of Neurology at Harvard Medical School and the lead investigator of the trial. “Data from previous controlled clinical trials of EPIDIOLEX have shown clinically meaningful seizure reductions and consistent safety and tolerability in children and adults with Lennox-Gastaut syndrome and Dravet syndrome. Based on the positive results of this trial in TSC patients, EPIDIOLEX, if approved for this additional indication, may become an important treatment option also in this disease state with significant unmet medical need.”

Higher Cannabidiol Plasma Levels are Associated with Better Seizure Response Following Treatment with a Pharmaceutical Grade Cannabidiol

OBJECTIVE: The objective of this study was to determine the relationship between cannabidiol (CBD) dose, CBD plasma level, and seizure control in a large open-label single-center study.

METHODS: All participants with treatment-refractory epilepsy participating in this expanded access program (EAP) were approached for participation. Highly purified grade CBD (Epidiolex®) dosing was weight-based and could be increased every 2 weeks by 5 mg/kg/day up to a maximum dosage of 50 mg/kg/day depending on tolerance and seizure control. Seizure counts were obtained at each visit with frequency calculated per 2-week periods. Cross-sectional plasma peak levels of CBD were obtained ~4h after dosing in consecutively presenting patients.

RESULTS: This study evaluated 56 adults and 44 children (100 total; 54 female) at two time points – one before initiating CBD and one at the time of CBD plasma level testing. There was a positive linear correlation between CBD dosage (range from 5 to 50 mg/kg/day) and level (range from 7.1-1200 ng/mL) in all participants (r = 0.640;  p < 0.001). The quantile regression model supported the notion of increased CBD levels being associated with improvement in seizure frequency after adjusting for age – specifically, a 100 ng/mL increase in CBD level was associated with approximately two counts reduction in seizure frequency per time period (1.87 96% confidence interval [CI] 0.34-3.39; p = 0.018). In participants with the same CBD level, differences in seizure improvement did not depend on age (p = 0.318).

CONCLUSIONS: In this open-label study, researchers found evidence of a linear correlation between cannabidiol (CBD) dosage and plasma levels, and that higher dose/levels are associated with a higher response rate for seizure improvement. Children and adults responded to CBD similarly. However, seizure control response rates suggest children may respond to lower dosages/plasma levels than adults. Findings reported in this study are specific to Epidiolex® and should not be extrapolated to other CBD products.

Cannabidiol May Have Beneficial Effects on Quality of Life in Adults with Treatment-Resistant Epilepsy, Regardless of Treatment Response

Treatment-resistant epilepsy (TRE) is associated with low quality of life (QOL). Cannabidiol (CBD) may improve QOL, but it is unclear if such improvements are independent of improvements in seizure control. The aim of this study was to compare QOL at baseline and after 1 year of treatment with CBD.

Researchers hypothesized that QOL would improve independent of changes in seizure frequency (SF) or severity, mood, or adverse events. They assessed QOL using Quality of Life in Epilepsy-89 (QOLIE-89) in an open-label study of purified CBD (Epidiolex®) for the treatment of TRE.

All participants received CBD, starting at 5 mg/kg/day and titrated to 50 mg/kg/day in increments of 5 mg/kg/day. The team collected QOLIE-89 in adult participants at enrollment and after 1 year of treatment, or at study exit if earlier. The team analyzed if the change in QOLIE-89 total score could be explained by the change in SF, seizure severity (Chalfont Seizure Severity Scale, CSSS), mood (Profile of Moods States, POMS), or adverse events (Adverse Event Profile, AEP). Associations among the variables were assessed using bivariate tests and multiple regression. 53 participants completed enrollment and follow-up testing, seven at study termination. Mean QOLIE-89 total score improved from enrollment (49.4 ± 19) to follow-up (57 ± 21.3; p = .004). Researchers also saw improvements in SF, POMS, AEP, and CSSS (all p < .01). Multivariable regression results showed QOLIE-89 at follow-up associated with improvements in POMS at follow- up (p = .020), but not with AEP, CSSS, or SF (p > .135).

Improvement in QOL after treatment with CBD is associated with better mood but not with changes in SF, seizure severity, or AEP. Cannabidiol may have beneficial effects on QOL and mood that are independent of treatment response.

Cannabidiol Reduces Seizures in Patients with Lennox-Gastaut Syndrome: Interim Analysis of an Open-Label Extension Study

Objective: Patients with Lennox-Gastaut syndrome (LGS) who completed 1 of 2 randomized, double-blind, placebo-controlled trials of add-on cannabidiol (CBD) (GWPCARE3, NCT02224560 or GWPCARE4, NCT02224690) were invited to enroll in an open-label extension (OLE) study evaluating the long-term safety and efficacy of CBD (GWPCARE5, NCT02224573). This study is an interim analysis of the safety, efficacy, and patient-reported outcomes from this trial.

Methods: Patients received a pharmaceutical formulation of highly purified CBD oral solution (Epidiolex; 100 mg/mL), titrated from 2.5 to 20 mg/kg/d over a 2-week titration period, in addition to their existing medications. Doses could be reduced if not tolerated or increased up to 30 mg/kg/d if thought to be of benefit.

Results: This interim analysis was based on a November 2016 data cut. Of 368 patients who completed treatment in GWPCARE3 and GWPCARE4, 366 (99.5%) enrolled in the OLE study (GWPCARE5). Median treatment duration was 38 weeks at a mean modal dose of 23 mg/kg/d. Most patients (92.1%) experienced adverse events (AEs), primarily of mild (32.5%) or moderate (43.4%) severity. The most common AEs were diarrhea (26.8%), somnolence (23.5%), and convulsion (21.3%). 35 patients (9.6%) discontinued treatment due to AEs. Liver transaminase elevations were reported in 37 patients (10.1%), of whom 29 were receiving concomitant valproic acid; 34 cases resolved spontaneously or with dose modification of CBD or concomitant medication. Median reduction from baseline in drop seizure frequency (quantified monthly over 12-week periods) ranged from 48% to 60% through week 48. Median reduction in monthly total seizure frequency ranged from 48% to 57% across all 12-week periods through week 48. 88% of patients/caregivers reported an improvement in the patient’s overall condition per the Subject/Caregiver Global Impression of Change scale.

Significance: In this study, long-term add-on cannabidiol treatment had an acceptable safety profile in patients with LGS and led to sustained reductions in seizures.

New Review Study Supports Ability of Epidiolex to Reduce Seizure Frequency in Dravet, Lennox-Gastaut Patients

The objective was to review the efficacy, safety, pharmacology and pharmacokinetics of pure, plant-derived cannabidiol (CBD; Epidiolex) in the treatment of Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS).

The review, “Epidiolex (Cannabidiol): A New Hope for Patients With Dravet or Lennox-Gastaut Syndromes,” was published in Annals of Pharmacotherapy.

“The frequency and severity of seizures have profound impacts on quality of life, risk for injury (eg, convulsive seizures in [Dravet syndrome], drop seizures in [Lennox-Gastaut syndrome]), health care use, and increased risk for mortality,” the researchers wrote.

It is carbohydrate neutral and compatible with ketogenic diets — a diet high in fats and low in carbs that has been shown to reduce the frequency of seizures and improve cognitive function in children with Dravet syndrome.

Previous clinical trials have found that Epidiolex effectively reduces the frequency of epileptic seizures when used in combination with other anti-epileptic medications.

Researchers in this study reviewed the main findings of these trials regarding the safety, efficacy, and tolerability of Epidiolex for the treatment of children with Dravet and Lennox-Gastaut syndromes.

Cannabidiol Improves Frequency and Severity of Seizures and Reduces Adverse Events in an Open-Label Add-On Prospective Study

The objective of this study was to characterize the changes in adverse events, seizure severity, and frequency in response to a pharmaceutical formulation of highly purified cannabidiol (CBD; Epidiolex®) in a large, prospective, single-center, open-label study.

Researchers initiated CBD in 72 children and 60 adults with treatment-resistant epilepsy (TRE) at 5?mg/kg/day and titrated it up to a maximum dosage of 50?mg/kg/day. At each visit, they monitored treatment adverse events with the adverse events profile (AEP), seizure severity using the Chalfont Seizure Severity Scale (CSSS), and seizure frequency (SF) using seizure calendars.

Data for the enrollment and visits at 12, 24, and 48?weeks was analyzed. Researchers recorded AEP, CSSS, and SF at each follow-up visit for the weeks preceding the visit (seizures were averaged over 2-week periods). Of the 139 study participants in this ongoing study, at the time of analysis, 132 had 12-week, 88 had 24-week, and 61 had 48-week data. Study retention was 77% at one year.

There were no significant differences between participants who contributed all 4 data points and those who contributed 2 or 3 data points in baseline demographic and AEP/SF/CSSS measures. For all participants, AEP decreased between CBD initiation and the 12-week visit (40.8 vs. 33.2; p?<?0.0001) with stable AEP scores thereafter (all p???0.14). Chalfont Seizure Severity Scale scores were 80.7 at baseline, decreasing to 39.2 at 12?weeks (p?<?0.0001) and stable CSSS thereafter (all p???0.19). Bi-weekly SF decreased from a mean of 144.4 at entry to 52.2 at 12?weeks (p?=?0.01) and remained stable thereafter (all p???0.65). Analyses of the pediatric and adult subgroups revealed similar patterns. Most patients were treated with dosages of CBD between 20 and 30?mg/kg/day.

For the first time, this prospective, open-label safety study of CBD in treatment-resistant epilepsy provides evidence for significant improvements in the adverse event profile, Chalfont seizure severity scale, and seizure frequency at 12?weeks that are sustained over the 48-week duration of treatment.