Developmental and Epileptic Encephalopathies (DEE) - Market Insight, Epidemiology and Market Forecast - 2034

Key Highlights

• The total market size in the 7MM for Developmental and Epileptic Encephalopathy (DEE) was estimated to be nearly USD 2.10 billion in 2023, which is expected to grow with a significant CAGR during the forecast period.
• In 2023, the US accounted for the maximum share of the total market in the 7MM, i.e., approximately 80%.
• The current understanding of these syndromes poses challenges for clinicians aiming to achieve the primary treatment goal of improving overall neurological outcomes. Conventional antiepileptic drugs often fall short in this regard, prompting a shift in treatment focus toward steroids and other immunomodulatory therapies.
• Over the past decade, significant efforts have been dedicated to developing new treatment options for DEEs. Several therapies have recently gained approval, such as EPIDIOLEX (cannabidiol), designated as an orphan drug for Dravet syndrome, Tuberous Sclerosis Complex (TSC), and Lennox-Gastaut syndrome (LGS). Additionally, everolimus is a possible antiepileptogenic and precision drug for tuberous sclerosis complex, with its impact on the mammalian target of the rapamycin pathway.
• Currently, ZETALMY is the sole FDA-approved drug for treating CDK5L deficiency disorder, benefiting from market exclusivity. However, this exclusive status is expected to face competition within the next 2-3 years as FINTEPLA, another promising therapeutic candidate, is anticipated to enter the market. This upcoming introduction highlights the evolving landscape of treatments for rare genetic disorders, offering new hope for patients and caregivers.
• Most current therapies for DEE focus on treating specific conditions like Dravet syndrome, LGS, CDKL5 deficiency disorder, and TSC. These therapies represent only a small part of the broader DEE landscape. There are over 20 other DEE subtypes that remain largely unexplored, representing a significant untapped market with substantial potential for companies developing new treatments.
• The market growth of DEE may be offset by failures and discontinuation of emerging therapies, unaffordable pricing, market access and reimbursement issues, and a scarcity of healthcare specialists.
• The DEE indication has a strong pipeline, with many companies actively developing DEE therapies. Key players include Takeda, Eisai, SK Life Science, Stoke Therapeutics, Harmony Biosciences/Epygenix, Longboard Pharmaceuticals, Praxis Precision Medicines, Neurocrine Biosciences, Bright Minds Biosciences, Cerecin, Encoded Therapeutics, Bloom Science, IAMA Therapeutics, Ultragenyx Pharmaceutical, Neuroene Therapeutics, and Regel Therapeutics, among others..

This report delivers an in-depth understanding of DEE, historical and forecasted epidemiology as well as DEE market trends in the United States, EU4 (Germany, France, Italy, and Spain) and the United Kingdom, and Japan.

The DEE market report provides current treatment practices, emerging drugs, market share of individual therapies, and current and forecasted 7MM DEE market size from 2020 to 2034. The report also covers current DEE treatment practices/algorithms and unmet medical needs to curate the best opportunities and assess the market’s potential.

Geography Covered

• The United States
• EU4 (Germany, France, Italy, and Spain) and the United Kingdom
• Japan

DEE Understanding and Treatment Algorithm

DEE Overview

Developmental and Epileptic Encephalopathy (DEE) refers to a group of severe epilepsies that are characterized both by seizures, which are often drug-resistant, as well as encephalopathy, which is a term used to describe significant developmental delay or even loss of developmental skills. Developmental encephalopathy implies that developmental delays are the direct result of the underlying cause of their epilepsy. In addition, some children with DEEs also have epileptic encephalopathy due to very frequent seizures and markedly abnormal electroencephalographs, which may substantially worsen developmental problems.

The syndromes of epileptic encephalopathies with onset in the neonatal period, infancy, and early childhood include Dravet syndrome (severe myoclonic epilepsy in infancy), LGS, CDKL5 Deficiency Disorder (CDD), TSC, DUP15q syndrome, SCN2A-DEE, SCN8A-DEE, KCNQ2-DEE, KCNQ3-DEE, Angelman syndrome, Landau-Kleffner Syndrome (LKS), Early Myoclonic Encephalopathy, KCNT1-DEE, Rett syndrome, Ohtahara syndrome, PCDH19, EE w/continuous spike-wave, Myoclonic Atonic Epilepsy, Ring20 and others.

DEE Diagnosis

Diagnosing epilepsy is not always easy. The doctor usually considers the person’s background and medical history, conducts a physical examination, as well as refers them for tests and investigations, to assess the type of seizures and make a diagnosis. Medical tests that are used in the diagnosis of epilepsy include blood tests, EEG (electroencephalogram), CT scan (Computerized Tomography), and/or an MRI (Magnetic Resonance Imaging).

Tests may be performed to: confirm the doctor’s suspicion, determine the type of seizure or epilepsy, determine the most appropriate treatment for the child’s condition, determine the underlying cause of the child’s epilepsy, monitor the treatment of the child’s epilepsy, and assess associated mental health or behavioral problems.

DEE Treatment

The epilepsy syndromes at high risk are a group of conditions characterized by epileptic seizures that are difficult to treat and have developmental delays. The approach to the treatment of epileptic encephalopathy has some of the general principles and approaches to pediatric epilepsy treatment. The most appropriate anti-epileptic treatment is selected based on the type of epilepsy syndrome.

Anti-seizure medications are routinely used, but some types of seizures are usually difficult to control. It is the primary way in which epileptic seizures are controlled and is almost always the first class of therapy medications which include: Clobazam, Vigabatrin, Topiramate, Levetiracetam, Zonisamide, Phenobarbital, Cannabidiol, Stiripentol, Ethosuximide, Carbamazepine, Lamotrigine, Benzodiazapines, Clonazepam, Diazepam, Lorazepam, Nitrazepam, Phenobarbitone, Succinimides, Valproic acid, Rufinamide, and Felbamate.

Steroid therapy with Adrenocorticotropic hormone (ACTH) or prednisone has been helpful in some children. Steroids are often an effective treatment for the West’s syndrome. There have been few reports of steroid use in children with epilepsy outside the first year of life. Several studies suggest that the intravenous methylprednisolone pulse therapy regimen induces a statistically significant reduction of seizure frequency in children with epileptic encephalopathy.

Epilepsy surgery is carried out on the brain to treat epilepsy. This may involve removing a specific area of the brain that might have caused the epilepsy. There are different types of surgery, which are: Respective surgery, Disconnection surgery, and Laser Interstitial Thermal Therapy (LITT).

DEE Epidemiology

The DEE epidemiology chapter in the report provides historical as well as forecasted epidemiology segmented by total diagnosed prevalent cases of DEE, DEE Cases by subtypes in the 7MM covering the United States, EU4 (Germany, France, Italy, and Spain), United Kingdom, and Japan from 2020 to 2034.

• The total number of diagnosed prevalent cases of DEE in the 7MM was nearly 284,000 cases in 2023 and are projected to increase during the forecasted period.
• Lennox-Gastaut syndrome (LGS) and Tuberous sclerosis complex (TSC) asscociated epilepsy are the largest contributors to the overall DEE pool. The prevalent cases of DEE in the United States were nearly 50,000 for LGS and nearly 47,100 for TSC with epilepsy in 2023.
• The total number of cases in EU4 and the UK for DEE was estimated to be nearly 104,000 cases in 2023.
• Among EU4 and the UK, the highest number of cases for DEE was found in Germany which was estimated to nearly 34% of cases in EU4 and the UK in 2023.
• The total number of cases in Japan for DEE was estimated to be nearly 34,000 cases in 2023.

DEE Drug Chapters

The drug chapter segment of the DEE report encloses a detailed analysis of the marketed and the late, mid and early stage (Phase III, Phase II Phase I/II and Phase I) pipeline drug. The marketed drugs segment encloses drugs such as ZTALMY (ganaxolone), FINTEPLA (fenfluramine), EPIDIOLEX (cannabidiol), AFINITOR DISPERZ, DIACOMIT (stiripentol), and H.P. ACTHAR GEL. The drug chapter also helps understand the DEE clinical trial details, expressive pharmacological action, agreements and collaborations, approval and patent details, and the latest news and press releases.

Marketed Drugs

EPIDIOLEX (cannabidiol): Jazz Pharmaceuticals

EPIDIOLEX, also known as EPIDYOLEX in Europe, is the first prescription, plant-derived cannabis oral formulation developed by GW Pharmaceuticals. It is a novel class of antiepileptic medications with a different mechanism of action. The drug is the first FDA-approved drug that contains a purified drug substance derived from marijuana, and the active ingredient is cannabidiol (CBD). Under the Controlled Substances Act (CSA), CBD is classified as a Schedule I substance; thus, GW Pharmaceuticals conducted nonclinical and clinical studies to assess the abuse potential of CBD to support its usage.

In June 2018, EPIDIOLEX was approved by the US FDA for the treatment of LGS or Dravet syndrome in patients 2 years of age or older. The drug was launched in the US in November 2018, and in 2020 FDA approved EPIDIOLEX to treat seizures associated with TSC in patients 1 year and older.

In September 2019, the cannabidiol (CBD) oral solution was approved by the European Medical Agency (EMA) and received marketing authorization under the trade name EPIDYOLEX as adjunctive therapy for seizures associated with LGS or Dravet syndrome, in conjunction with clobazam for patients 2 years of age and older. In 2021, the EMA approved EPIDIOLEX to treat seizures associated with TSC in patients 2 year and older.

Recently, in August 2024, EPIDIOLEX did not meet the primary efficacy endpoint of a pre-specified percentage change in indication-associated seizure frequency during the treatment period (up to 16 weeks) compared to baseline in Japanese pediatric patients; however, numeric improvements were observed in the primary and several secondary endpoints. No new safety signals were observed in the trial. The company is continuing to collect data on Japanese patients and plans to engage with regulatory authorities in Japan regarding a potential new drug application (JNDA).

FINTEPLA (fenfluramine): UCB

FINTEPLA (formerly known as ZX008) is an oral medication that is a low-dose solution of fenfluramine hydrochloride. It prevents the entry of calcium ions into nerve cells, lowering their over-excitability and reducing seizure episodes. It also activates serotonin receptors, which contribute to the overall antiepileptic action.

In the United States, FINTEPLA is available only through a restricted distribution program called the FINTEPLA REMS program. FINTEPLA is available in the EU under a controlled access program requested by the EMA to prevent off-label use for weight management and to confirm that prescribing physicians have been informed of the need for periodic cardiac monitoring in patients taking FINTEPLA.

In February 2023 FINTEPLA was approved in the European Union for the treatment of seizures associated with LGS as an add-on therapy to other anti-epileptic medicines for patients 2 years of age and older, and in March 2022, the US FDA approved FINTEPLA for the treatment of seizures associated with LGS in patients 2 years of age and older

UCB Biosciences is aiming to expand the use of FINTEPLA to treat CDKL5 Deficiency Disorder, with the company currently conducting a Phase III trial for this indication. The trial's primary completion date is set for February 2025

Emerging Drugs

Zorevunersen (STK-001): Stoke Therapeutics

Zorevunersen is an investigational new medicine for the treatment of Dravet syndrome. It is a proprietary antisense oligonucleotide (ASO) and has the potential to be the first disease-modifying therapy to address the genetic cause of Dravet syndrome. The drug is designed to upregulate NaV1.1 protein expression by leveraging the non-mutant copy of the SCN1A gene to restore physiological NaV1.1 levels, thereby reducing both occurrences of seizures and significant non-seizure comorbidities. This RNA-based approach is not gene therapy but rather RNA modulation, as it does not manipulate nor insert genetic deoxyribonucleic acid (DNA). STK-001 has been granted orphan drug designation by the FDA and the EMA and rare pediatric disease designation by the FDA as a potential new treatment for Dravet syndrome.

Stoke Therapeutics’s discussions with global regulatory agencies are underway. The company is on track to provide a regulatory update on Phase III registrational plans for zorevunersen in the second half of 2024.

Bexicaserin (LP352): Longboard Pharmaceuticals

Bexicaserin is an oral, centrally acting, 5-HT2c superagonist in development for the potential treatment of seizures associated with DEEs such as Dravet syndrome, LGS, tuberous sclerosis complex (TSC), CDKL5 deficiency disorder (CDD), and other epileptic disorders. LP352 is designed to modulate GABA and, as a result, suppress the central hyperexcitability that is characteristic of seizures. LP352 is the only 5-HT2c receptor superagonist being dose-optimized for the refractory epilepsy population.

Longboard plans to advance bexicaserin (LP352) into a global Phase III program. The company also reported positive topline data from a Phase Ib/IIa clinical trial (the PACIFIC Study) evaluating bexicaserin in participants ages 12-65 years old with DEEs, including LGS, Dravet syndrome, and other DEEs.

Drug Class Insights

Antisense oligonucleotide

Disease-modifying therapies represent a significant leap forward in the treatment of Developmental and Epileptic Encephalopathies (DEE). These innovative approaches have the potential to transform the landscape of care, offering new hope to patients and families affected by these challenging conditions. For instance, if approved, STK-001 could become the first disease-modifying medicine for Dravet syndrome, a severe form of epilepsy. This breakthrough would not only address the symptoms but also target the underlying causes of the disease, marking the dawn of a new era in DEE treatment.

DEE Market Outlook

In recent years, three antiseizure medications have been approved as adjunct therapy in patients with Dravet Syndrome: DIACOMIT (Stiripentol), which was approved in the US in 2018 and received full European marketing authorization in 2014, EPIDIOLEX (cannabidiol) which was approved by the FDA in 2018, and FINTEPLA (fenfluramine), which was approved in 2020 in the US and EU. These treatments are “add-on” therapies (most usually used in conjunction with Valproate and clobazam) with availability and recommendations in various countries influencing the decision in the EU

New insights into the pathophysiology of DEE are paving the way for the exploration of novel and repurposed drugs in future patient management. For instance, FINTEPLA (Fenfluramine) has been repurposed as an innovative therapy for Dravet and Lennox-Gastaut syndrome. Additionally, the use of drugs tailored to specific genetic mutations exemplifies the growing field of applied pharmacogenetics. The landscape of drug development is shifting, moving from the creation of a limited number of medications aimed at a broad patient population - particularly those with focal onset or generalized tonic-clonic seizures in idiopathic generalized epilepsy - to the emergence of numerous candidate drugs specifically targeting orphan epilepsies. The shift by companies toward precision medicine is not only inherently more appealing but also holds the promise of addressing the entire disease, rather than merely controlling seizures, offering the potential for transformative outcomes.

To summarize, as a number of new medicines enter the market, the treatment paradigm for DEE is expected to evolve in the coming years. Demand for emerging therapies would be driven by physician enthusiasm, which a significant unmet need, frequent switching, and the usage of multi-drug regimens would fuel.

• The total market size in the US for DEE was estimated to be nearly USD 1.65 billion in 2023, which is expected to increase due to the launch of emerging therapies and label expansion of current therapies.
• Among EU4 and the UK, the highest market share for DEE was found in Germany which was estimated to nearly 35% of market share in EU4 and the UK in 2023.
• The market share of Japan for DEE was estimated to be nearly USD 80 million in 2023.
• In 2023, anti-epileptic drug captured the highest market size of approximately USD 900 million in the 7MM, followed by EPIDIOLEX/EPIDYOLEX.

Key Updates

• According to Jazz Pharmaceuticals' Q2 2024 report, published in July 2024, the company anticipates additional ex-US launches of EPIDIOLEX/EPIDYOLEX through 2024.
• As per Ovid Therapeutics' corporate presentation published in August 2024, despite soticlestat failure to meet its primary endpoint in a Phase III trial in Dravet syndrome, Takeda Pharmaceuticals is exploring a potential path to marketing authorization in Dravet syndrome with the US FDA. Takeda retains guidance that it may file soticlestat for approval in Dravet in its FY 2024.
• As per Marinus Pharmaceuticals Q2 2024 report, Orion Corporation continues to prepare for commercial launches of ZTALMY in select European countries in the H2 2024, with regulatory approvals secured in the European Union and United Kingdom for the CDD indication.
• In April 2024, Harmony Biosciences announced the acquisition of Epygenix Therapeutics, accelerating its growth strategy by adding a rare epilepsy franchise to its expanding late-stage pipeline of innovative CNS assets. The acquisition included clemizole hydrochloride (EPX-100), a potent, oral, centrally acting serotonin (5HT2) agonist currently in a pivotal registrational clinical trial for the treatment of Dravet syndrome in children and adults and poised to enter Phase III for the treatment of LGS.

DEE Drugs Uptake

This section focuses on the uptake rate of potential drugs expected to be launched in the market during 2020-2034. The landscape of DEE treatment has experienced a profound transformation with the uptake of novel drugs. These innovative therapies are redefining standards of care. Furthermore, the increased uptake of these transformative drugs is a testament to the unwavering dedication of physicians, oncology professionals, and the entire healthcare community in their tireless pursuit of advancing cancer care. This momentous shift in treatment paradigms is a testament to the power of research, collaboration, and human resilience.

Given to the label expansion and better efficacy results FINTEPLA is expected to capture the largest market share in the 7MM with a medium-fast uptake.

DEE Pipeline Development Activities

The report provides insights into therapeutic candidates in Phase III, Phase II, PhaseI/II, and Phase I. It also analyzes key players involved in developing targeted therapeutics.

Pipeline Development Activities

The report covers information on collaborations, acquisitions and mergers, licensing, and patent details for DEE emerging therapy.

KOL Views

To keep up with current market trends, we take KOLs and SMEs’ opinions working in the domain through primary research to fill the data gaps and validate our secondary research. Industry Experts contacted for insights on DEE evolving treatment landscape, patient reliance on conventional therapies, patient therapy switching acceptability, and drug uptake, along with challenges related to accessibility, including oncologists, radiation oncologists, surgical oncologists, and others.

The analysts connected with 30+ KOLs to gather insights; however, interviews were conducted with 15+ KOLs in the 7MM. Centers such as - Azienda Sanitaria Universitaria Friuli Centrale, Dravet Syndrome Foundation Spain, University of Colorado, Neurology at Children's Hospital Colorado, Child Neurology Residency and the Pediatric Epilepsy Fellowship at Children's Hospital of Philadelphia, Saint Louis University School of Medicine etc., were contacted. Their opinion helps understand and validate current and emerging therapy treatment patterns or DEE market trends. This will support the clients in potential upcoming novel treatments by identifying the overall scenario of the market and the unmet needs.

Qualitative Analysis

We perform Qualitative and market Intelligence analysis using various approaches, such as SWOT analysis. In the SWOT analysis, strengths, weaknesses, opportunities, and threats in terms of disease diagnosis, patient awareness, patient burden, competitive landscape, cost-effectiveness, and geographical accessibility of therapies are provided. These pointers are based on the Analyst’s discretion and assessment of the patient burden, cost analysis, and existing and evolving treatment landscape.

Market Access and Reimbursement

EPIDIOLEX Co-pay Savings Program

The co-pay savings program is designed to help make EPIDIOLEX affordable and accessible for eligible commercially insured patients. Eligible commercially insured patients may pay as low as USD 0 per prescription.

DIACOMIT Co-pay Savings Program

Eligibility criteria

• USD 0 co-pay per prescription.
• For eligible patients with commercial insurance.
• Not available for government plans such as Medicare or Medicaid

ZTALMY One Prescription Support Programs

If your child has no insurance, limited insurance, or a gap or delay in coverage, ZTALMY One Prescription Support Programs may be able to help with the cost of treatment with ZTALMY. It is worth highlighting that a Rare Pediatric Disease Priority Review Voucher (PRV) was awarded to Marinus by the US FDA upon approval of ZTALMY. The company intends to monetize the PRV to fund ongoing operations, including continued clinical development and commercialization efforts for ganaxolone

Scope of the Report

• The report covers a segment of key events, an executive summary, and a descriptive overview of DEE, explaining its causes, signs, symptoms, pathogenesis, and currently used therapies.
• Comprehensive insight into the epidemiology segments and forecasts, disease progression, and treatment guidelines has been provided.
• Additionally, an all-inclusive account of the emerging therapies and the elaborative profiles of late-stage and prominent therapies will impact the current treatment landscape.
• A detailed review of the DEE market, historical and forecasted market size, market share by therapies, detailed assumptions, and rationale behind our approach is included in the report, covering the 7MM drug outreach.
• The report provides an edge while developing business strategies, by understanding trends, through SWOT analysis and expert insights/KOL views, patient journey, and treatment preferences that help shape and drive the 7MM DEE market.

DEE Report Insights

• Patient Population
• Therapeutic Approaches
• DEE Pipeline Analysis
• DEE Market Size and Trends
• Existing and Future Market Opportunity

DEE Report Key Strengths

• Eleven Years Forecast
• The 7MM Coverage
• DEE Epidemiology Segmentation
• Key Cross Competition
• Drugs Uptake and Key Market Forecast Assumptions

DEE Report Assessment

• Current Treatment Practices
• Unmet Needs
• Pipeline Product Profiles
• Market Attractiveness
• Qualitative Analysis (SWOT Analysis and Conjoint Analysis)

FAQs

• What was the DEE market size, the market size by therapies, market share (%) distribution in 2023, and what would it look like by 2034? What are the contributing factors for this growth?
• What are the pricing variations among different geographies for approved therapies?
• What can be the future treatment paradigm of DEE?
• What are the disease risk, burdens, and unmet needs of DEE? What will be the growth opportunities across the 7MM concerning the patient population with DEE?
• Who is the major competitor of EPIDIOLEX in the market?
• What are the current options for the treatment of DEE? What are the current guidelines for treating DEE in the US, Europe, and Japan?
• What are the recent novel therapies, targets, mechanisms of action, and technologies being developed to overcome the limitation of existing therapies?

Reasons to Buy

• The report will help develop business strategies by understanding the latest trends and changing treatment dynamics driving the DEE market.
• Insights on patient burden/disease prevalence, evolution in diagnosis, and factors contributing to the change in the epidemiology of the disease during the forecast years.
• Understand the existing market opportunity in varying geographies and the growth potential over the coming years.
• Distribution of historical and current patient share based on real-world prescription data along with reported sales of approved products in the US, EU4 (Germany, France, Italy, and Spain), the United Kingdom, and Japan.
• Identifying strong upcoming players in the market will help devise strategies to help get ahead of competitors.
• Detailed analysis and ranking of class-wise potential current and emerging therapies under the Analyst view section to provide visibility around leading classes.
• Highlights of access and reimbursement policies of current therapies, barriers to accessibility of expensive off-label therapies, and patient assistance programs.
• To understand Key Opinion Leaders’ perspectives around the accessibility, acceptability, and compliance-related challenges of existing treatment to overcome barriers in the future.
• Detailed insights on the unmet need of the existing market so that the upcoming players can strengthen their development and launch strategy.