Treating Severe Childhood Epilepsy with Fenfluramine
This patent describes a specific way to treat Lennox-Gastaut Syndrome, a severe form of childhood epilepsy, by giving patients a controlled dose of the drug fenfluramine.
Original patent title: “Methods of treating Lennox-Gastaut Syndrome using fenfluramine”
This patent describes a specific way to treat Lennox-Gastaut Syndrome, a severe form of childhood epilepsy, by giving patients a controlled dose of the drug fenfluramine. Granted in 2026.
Coverage
What does this patent actually cover?
This patent describes a method for treating or preventing symptoms of Lennox-Gastaut Syndrome (LGS), a severe type of epilepsy, in a patient. The method involves giving the patient an effective dose of fenfluramine or its pharmaceutically acceptable salt. Specifically, the patent mentions a preferred dosage range for LGS patients of less than about 2.0 to about 0.01 milligrams per kilogram of body weight per day. For example, a child previously diagnosed with LGS would receive fenfluramine within this precise daily dosage range to help manage their seizures.
The gap
What does this patent NOT cover?
- Does not cover using fenfluramine to treat other types of epilepsy or medical conditions not identified as Lennox-Gastaut Syndrome.
- Does not cover treating Lennox-Gastaut Syndrome with other medications that are not fenfluramine or its pharmaceutically acceptable salts.
- Does not cover administering fenfluramine at dosages outside the specified range of less than about 2.0 to about 0.01 mg/kg/day for LGS.
- Does not cover methods of preventing LGS symptoms that do not involve administering fenfluramine.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → lies in identifying fenfluramine, a drug with a complex history, as an effective treatment for Lennox-Gastaut Syndrome at a specific, carefully defined low dosage. This precise application to a rare, difficult-to-treat epilepsy was not widely recognized before.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Fintepla (fenfluramine) oral solution for Lennox-Gastaut Syndrome
Treatments for severe childhood epilepsies
Why it matters
The bigger picture
Lennox-Gastaut Syndrome is a rare and severe form of childhood epilepsy that is often resistant to many standard treatments, leading to frequent seizures and developmental delays. Finding effective treatments for LGS is crucial for improving the quality of life for patients and their families. This patent focuses on a specific drug, fenfluramine, which has shown efficacy in managing this challenging condition.
Filed
May 1, 2020
Granted
September 15, 2026
Market context
Who's building on this
Companies in this space
The company Zogenix developed fenfluramine (marketed as Fintepla) for the treatment of Lennox-Gastaut Syndrome and Dravet syndrome. Zogenix was later acquired by UCB, a global biopharmaceutical company. UCB continues to research and develop treatments for severe neurological conditions, building on the understanding of drugs like fenfluramine.
Market impact
This patent's subject matter helped expand the therapeutic options available for patients suffering from Lennox-Gastaut Syndrome, a condition with limited effective treatments. The introduction of fenfluramine for LGS provided a new mechanism of action and an important tool for clinicians. This has allowed for better seizure control in some patients, improving their daily lives and potentially reducing the burden on caregivers and healthcare systems.
Claim 1 — Plain English
What this patent covers
This patent describes a method for treating or preventing symptoms of Lennox-Gastaut Syndrome (LGS), a severe type of epilepsy, in a patient. The method involves giving the patient an effective dose of fenfluramine or its pharmaceutically acceptable salt. Specifically, the patent mentions a preferred dosage range for LGS patients of less than about 2.0 to about 0.01 milligrams per kilogram of body weight per day. For example, a child previously diagnosed with LGS would receive fenfluramine within this precise daily dosage range to help manage their seizures.
The clever bit
The novelty lies in identifying fenfluramine, a drug with a complex history, as an effective treatment for Lennox-Gastaut Syndrome at a specific, carefully defined low dosage. This precise application to a rare, difficult-to-treat epilepsy was not widely recognized before.
What it does not cover
- Does not cover using fenfluramine to treat other types of epilepsy or medical conditions not identified as Lennox-Gastaut Syndrome.
- Does not cover treating Lennox-Gastaut Syndrome with other medications that are not fenfluramine or its pharmaceutically acceptable salts.
- Does not cover administering fenfluramine at dosages outside the specified range of less than about 2.0 to about 0.01 mg/kg/day for LGS.
- Does not cover methods of preventing LGS symptoms that do not involve administering fenfluramine.
Patent timeline
Application submitted to the patent office
Patent officially issued
PatentBrief Score
Impact Score
Early stage
Citation count
0/40
No citations yet
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
20/20
Granted within 5 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$36K – $115K
Midpoint $72K · 13.6 yr remaining · industry ×3.0
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
Concepts involved
Cite this patent
(2026). Treating Severe Childhood Epilepsy with Fenfluramine (U.S. Patent No. 12,734,137). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/12734137/methods-of-treating-lennox-gastaut-syndrome-using-fenfluramine
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does Treating Severe Childhood Epilepsy with Fenfluramine cover?
This patent describes a specific way to treat Lennox-Gastaut Syndrome, a severe form of childhood epilepsy, by giving patients a controlled dose of the drug fenfluramine.
When does this patent expire?
This patent is expected to expire on September 15, 2046, when the invention enters the public domain.
What problem does this patent solve?
Lennox-Gastaut Syndrome is a rare and severe form of childhood epilepsy that is often resistant to many standard treatments, leading to frequent seizures and developmental delays. Finding effective treatments for LGS is crucial for improving the quality of life for patients and their families. This patent focuses on a specific drug, fenfluramine, which has shown efficacy in managing this challenging condition.
What does this patent NOT cover?
Does not cover using fenfluramine to treat other types of epilepsy or medical conditions not identified as Lennox-Gastaut Syndrome.
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