Zogenix Ready to Resubmit Fintepla for Rare Epilepsy to FDA

In April, the FDA issued a Refuse to File (RTF) letter to Zogenix for its New Drug Application (NDA) for Fintepla (fenfluramine hydrochloride). The drug was developed to treat seizures associated with Dravet syndrome, a rare form of epilepsy characterized by frequent and prolonged seizures.

The company at the time indicated the application, which was submitted in February, was not “sufficiently complete to permit a substantive review.” The FDA had two concerns, the first over non-clinical studies that were not submitted over chronic administration of the drug, and what Zogenix indicated as an incorrect version of a clinical dataset.

Now, the company announced that after its Type A meeting with the FDA on May 30, it plans to resubmit its NDA for Fintepla. Based on the meeting, the company will resubmit the NDA without the inclusion of the new chronic toxicity studies requested in the original RTF letter. In terms of the second issue, Zongenix ran a root cause analysis to explain the incorrect clinical dataset originally submitted and discussed that analysis with the agency.

“We are very pleased with the outcome of our meeting with the FDA and appreciate their thoughtful approach in considering the totality of the data from our drug development program, along with additional clinical and non-clinical literature that will be referenced in our re-submission,” stated Stephen J. Farr, president and chief executive officer of Zogenix. “We now have the clarity required to successfully resubmit our Fintepla NDA, which we will anticipate will occur in the third quarter.”

Clinical Evolution and Epilepsy Outcome in Three Patients with CDKL5-Related Developmental Encephalopathy

Objective: To further characterize CDKL5-related disorder, previously classified as an early-onset seizure variant of Rett syndrome, which is currently considered a specific and independent early-infantile epileptic encephalopathy.

Results: Researchers describe the epileptic phenotype and neurocognitive development in three girls with CDKL5 mutations showing severe neurodevelopmental impairment, with different epileptic phenotypes and severity. The patients differed regarding age at epilepsy onset, seizure frequency, duration of “honeymoon periods”, as well as EEG features. The “honeymoon period”, defined as a seizure-free period longer than two months, represented, in this case series, a good indicator of the epilepsy outcome, but not of the severity of developmental impairment. However, even during the “honeymoon period”, the interictal EEG showed epileptiform abnormalities, slowing, or a disappearance of physiological pattern. The natural history of CDKL5 disorder was compared between the three girls, focusing on the relationship between electroclinical features and neurological development.

Significance: These findings suggest that CDKL5 mutations likely play a direct role in psychomotor development, whereas epilepsy is one of the clinical features associated with this complex disorder.

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.

AZD7325 Has Seizure-Protective Effect in Mouse Model of Dravet Syndrome, Study Says

Treatment with AZD7325, a compound that stimulates the activity of a specific type of receptor in the brain, has a seizure-protective effect in a mouse model of Dravet syndrome, a study has found.

The study was published in The Journal of Physiology.

In this study, a group of researchers from Northwestern University in Chicago, Illinois, set out to test the effects of AZD7325, a potentiator of a subtype of GABAA receptors containing the alpha 2 or 3 subunits, in different strains of a mouse model of Dravet syndrome. Of note, GABAA receptors are composed of numerous different subunits, which determine the receptors’ affinity to certain molecules, among other properties.

Treatment with AZD7325 significantly increased the temperature threshold animals were able to withstand without experiencing any seizures during an hyperthermia-induced seizure test. This seizure-protective effect was present in all three doses tested (10 mg/kg; 17.8 mg/kg; and 31.6 mg/kg) and was not associated with sedative side effects.

New Drug Could Help Treat Neonatal Seizures

A new drug that inhibits neonatal seizures in rodent models could open up new avenues for the treatment of epilepsy in human newborns. Researchers have identified 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. A paper describing the research, from an international team of scientists led by Penn State researchers, appears May 15, 2019 in the journal Molecular Brain.

“Neonates are the most vulnerable population to seizures but there is still no effective medication for the treatment of neonatal epilepsy,” said Gong Chen, professor of biology and the Verne M. Willaman Chair in Life Sciences at Penn State and the leader of the research team. “The incidence of epilepsy is highest in the first year of life, with two to four infant babies suffering from neonatal epilepsy for every 1,000 live births in the United States. Unfortunately, so far there is no effective drug available that is specifically developed for neonatal epilepsy patients.”

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.

Is Targeting of Compensatory Ion Channel Gene Expression a Viable Therapeutic Strategy for Dravet Syndrome?

Loss of function in the Scn1a gene leads to a severe epileptic encephalopathy called Dravet syndrome (DS). Reduced excitability in cortical inhibitory neurons is thought to be the major cause of DS seizures. Here, in contrast, researchers show enhanced excitability in thalamic inhibitory neurons that promotes the nonconvulsive seizures that are a prominent yet poorly understood feature of DS. In a mouse model of DS with a loss of function in Scn1a, reticular thalamic cells exhibited abnormally long bursts of firing caused by the downregulation of calcium-activated potassium SK channels.

The authors claim that this study supports a mechanism in which loss of potassium SK channel activity causes the reticular thalamic neurons to become hyperexcitable and promote nonconvulsive seizures in DS. They propose that reduced excitability of inhibitory neurons is not global in Dravet syndrome and that non-GABAergic mechanisms such as SK channels may be important targets for treatment.

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.”

Are Febrile Seizures Associated With Increased Sudden Death Risk in Young Children?

Children with febrile seizures (FS) have a small yet elevated risk for death. Recent data suggest that FS may contribute to sudden unexplained death in childhood (SUDC) among cases of sudden explained death in childhood (SEDC). This is according to findings published in JAMA Network Open from one of the largest studies of its kind exploring the role of FS and other risk factors in SUDC.

A total of 622 consecutive cases of sudden child death that occurred from 2001 to 2017 were included in the review. Data were collected from voluntary records of family members who were registered with the SUDC Foundation. The final cause of death resulted in cases categorized as either SEDC or SUDC. The main outcome measure included the certified manner of death as accident, natural, or undetermined.

Alternative Treatment for Epileptic Seizures in Children Identified

A new study published in The Lancet, involving researchers from the University of Liverpool and Alder Hey Children’s Hospital Trust, has identified a ‘user friendly’ treatment for the most common life-threatening neurological emergency in children.

Convulsive status epilepticus (CSE) is the situation when a tonic-clonic seizure doesn’t stop either on its own or with anticonvulsants. It is the most common life-threatening neurological emergency in children.

Currently, CSE is treated using an algorithm which incorporates 10 min intervals between treatments. Second-line treatment is given when CSE persists either after two doses of the first-line treatment, which is an anticonvulsant called a benzodiazepine, or the child’s personalized emergency (rescue) treatment.

The anticonvulsant medication phenytoin has been used as the usual second-line treatment of CSE for several decades and is known to have rare but potentially dangerous side effects. However, some evidence suggests that another medication, levetiracetam could be an effective and safer alternative. To ascertain which treatment was safest and most effective the EcLiPSE Team, made up of doctors from Alder Hey and Bristol Children’s Hospitals together with research teams from the Universities of Liverpool and the West of England, conducted a trial to compare the efficacy and safety of both drugs for second-line management of CSE.

“Our results suggest that levetiracetam could be considered as an alternative treatment to phenytoin for second-line management of pediatric CSE. Possible benefits of levetiracetam over phenytoin include its ease of preparation and administration, minimal interaction with antiepilepsy and other drugs, and easy conversion to oral maintenance therapy. Further randomised clinical trial and meta-analysis data could help to confirm our results and might lead to levetiracetam being the preferred second-line anticonvulsant in children with benzodiazepine-resistant convulsive status epilepticus.