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May 02
JAMA Neurology Publishes Phase 3 Study Results on the Efficacy and Safety of FINTEPLA® (fenfluramine) Oral Solution in Lennox-Gastaut Syndrome (LGS)

This Press Release is Intended for Media and Investor Stakeholders Only

  • Primary endpoint was met demonstrating that FINTEPLA, as adjunctive treatment, is effective in significantly reducing the frequency of drop seizures in LGS patients compared to placebo1
  • The peer-reviewed published data reinforce the clinical profile of FINTEPLA and its value as a new and important treatment option for LGS patients, particularly for those experiencing generalized tonic-clonic seizures (GTCs)1
  • LGS is a severe childhood-onset developmental and epileptic encephalopathy characterized by drug-resistant seizures with high morbidity2
  • FINTEPLA was recently approved by the U.S. Food and Drug Administration (FDA), as a treatment option for the treatment of seizures associated with a LGS5

Brussels (Belgium) and Atlanta, Ga., May 2, 1:00 pm ET – UCB (Euronext: UCB) today announced the publication in JAMA Neurology of its multi-center, double-blind, placebo-controlled, parallel-group, randomized Phase 3 trial demonstrating that FINTEPLA 0.7 mg/kg/day, when added to a patient’s current anti-epileptic treatment regimen for seizures associated with LGS, is effective in reducing the frequency of drop seizures.1  Drop seizures cause a person to suddenly lose muscle tone, become limp, and fall to the ground, with a high likelihood of injury.6 Within the study, drop seizures were further defined as GTC, secondary GTC [focal to bilateral tonic clonic], tonic, atonic, or tonic and atonic.1

LGS is a severe childhood-onset developmental and epileptic encephalopathy characterized by drug-resistant seizures with high morbidity2 as well as serious impairment of neurodevelopmental, cognitive and motor functions.3 LGS has far-reaching effects beyond seizures, including issues with communication, psychiatric symptoms, sleep, behavioral challenges and mobility.7 LGS affects 30,000-50,000 patients in the U.S.8

The trial met its primary efficacy endpoint. Patients taking FINTEPLA 0.7 mg/kg/day experienced an estimated mean difference in the reduction of drop seizure frequency by 19.9% from placebo (P=.001). The median percent reduction in the frequency of drop seizures in the 0.7 mg/kg/day group was 26.5%, compared with 14.2% in the 0.2 mg/kg/day group, and 7.6% in patients taking placebo (P=.09). In key secondary outcomes, the trial demonstrated that a greater proportion of patients taking FINTEPLA experienced a 50% or greater reduction in drop seizure frequency, compared with patients in the placebo group.   

“Our trial data and the clinical evidence demonstrates the safety and efficacy of FINTEPLA in LGS and especially for patients where generalized tonic-clonic seizures are the predominant seizure type, where there is a greater risk of mortality,” said Kelly Knupp, M.D., MSCS, FAES, Associate Professor, Children’s Hospital Colorado, Principal Investigator of the study. “LGS is a highly treatment-resistant developmental and epileptic encephalopathy and we need differentiated treatment options, such as FINTEPLA, which has a unique mechanism of action different from and complementary to current anti-seizure medications.”

The study also included a seizure-type subgroup analyses that demonstrated that FINTEPLA 0.7 mg/kg/day was highly effective in reducing the frequency of GTCs in nearly 50% of patients. During the maintenance and titration period, patients experienced a decrease in frequency of 45.7% in the FINTEPLA 0.7 mg/kg/day group, a decrease in frequency of 58.2% in the 0.2 mg/kg/day FINTEPLA group, compared with an increase in frequency of 3.7% in the placebo group (P=.001 and P<.001 respectively). The percentage reduction in tonic or atonic seizure frequency was 46.7% in the FINTEPLA 0.7 mg/kg/day group, compared with 6.8% in the placebo group (P=.046).1

The reason these data are compelling is because GTCs are commonly observed in patients with LGS. Moreover, GTCs may result in bodily injury.10,11 Sudden unexpected death in epilepsy (SUDEP) is a major concern for people living with LGS, and patients with a history of GTCs have an estimated 10-fold greater risk of SUDEP.4

FINTEPLA was generally well-tolerated in this study. The most common treatment-emergent adverse events included decreased appetite, somnolence, and fatigue. The FINTEPLA safety database includes long-term cardiovascular safety data for patients treated for up to 3 years in Dravet syndrome (DS) and LGS.5

“This study further validates the importance of FINTEPLA as a new treatment option for seizures associated with LGS, including generalized tonic-clonic seizures,” said Mike Davis, Global Head of Epilepsy, UCB. “Through our close connection with the LGS community, we know the challenges they face go beyond treatment resistant seizures to include difficulty with behavior and cognition, and we hope that FINTEPLA can help people living with LGS.” 

Site investigators and caregivers also rated patients as significantly much or very much improved on the Clinical Global Impression of Improvement (CGI-I) scale (investigators 26% vs. 20% vs. 6% and caregivers 34% vs. 27% vs. 5% for 0.7 mg/kg vs. 0.2 mg/kg vs. placebo, respectively).1

FINTEPLA was approved by the U.S. FDA for the treatment of LGS in patients 2 years and older in March 2022 and was also approved for the treatment of DS in patients 2 years and older in June 2020. UCB acquired Zogenix, Inc. and FINTEPLA on March 7, 2022. The acquisition is consistent with UCB’s sustainable patient value strategy and continued commitment to providing world-leading patient value to all people living with epilepsy, with an increasing focus on creating value and new solutions that address the unmet needs of people with certain specialized or rare types of epilepsy, where few or no options exist.

Study Design
The multi-center, double-blind, placebo-controlled, parallel-group, randomized Phase 3 clinical trial was conducted from 27 November 2017 to 25 October 2019, and had a 20-week trial duration. Patients were enrolled at 65 study sites in North America, Europe, and Australia.  

A total of 263 patients were randomly assigned to receive either FINTEPLA 0.7 mg/kg/day (n=87) or FINTEPLA 0.2 mg/kg/day (n=89) or placebo (n=87). After titration (2-week period), patients were maintained on their randomized dose for 12 additional weeks. The median age was 13 years of age.

Children and adults, aged 2 to 35 years, with a confirmed LGS diagnosis who were using stable anti-seizure medication (ASM) regimens (≥1 and ≤4 concomitant ASMs) were eligible for enrollment if these criteria were met: onset of seizures at age 11 years or younger; multiple seizure types, including tonic and tonic or atonic seizures; stable 4-week seizure baseline with 2 of more drop seizures per week of GTC, or secondary GTC (i.e., focal to bilateral tonic-clonic seizures), tonic, atonic, or tonic or atonic seizure; abnormal cognitive development; and medical history showing electroencephalogram evidence of abnormal background activity with slow spike-and-wave pattern (<2.5Hz). Key exclusion criteria were degenerative neurological disease, history of hemiclonic seizures in the first year of life, only drop seizure clusters, previous or current exclusionary cardiovascular or cardiopulmonary abnormality or concomitant cannabidiol use (not FDA approved at time of study).

This study was funded by Zogenix, Inc., now part of UCB.  

About FINTEPLA® (fenfluramine) C-IV
FINTEPLA® (fenfluramine) oral solution is a prescription medication approved in the U.S. and Europe, and under regulatory review in Japan, for the treatment of seizures associated with Dravet syndrome in patients two years of age and older.12,13 FINTEPLA is also approved in the U.S. for the treatment of seizures associated with Lennox-Gastaut syndrome.5 Application for treatment of seizures associated with LGS has also been submitted and is currently under assessment by the European Medicines Agency (EMA).14

In the U.S., FINTEPLA is available only through a restricted distribution program called the FINTEPLA REMS program. FINTEPLA is available in Europe 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. Further information is available at www.FinteplaREMS.com or by telephone at 1-877-964-3649.

Please see full Prescribing Information, including Boxed Warning, for additional important information on FINTEPLA.


FINTEPLA is indicated for the treatment of seizures associated with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) in patients 2 years of age and older.



• There is an association between serotonergic drugs with 5-HT2B receptor agonist activity, including fenfluramine (the active ingredient in FINTEPLA), and valvular heart disease and pulmonary arterial hypertension.

• Echocardiogram assessments are required before, during, and after treatment with FINTEPLA.

• FINTEPLA is available only through a restricted program called the FINTEPLA REMS.


FINTEPLA is contraindicated in patients with hypersensitivity to fenfluramine or any of the excipients in FINTEPLA and with concomitant use, or within 14 days of the administration of monoamine oxidase inhibitors because of an increased risk of serotonin syndrome.


Valvular Heart Disease and Pulmonary Arterial Hypertension (see Boxed Warning): Because of the association between serotonergic drugs with 5–HT2B receptor agonist activity, including fenfluramine (the active ingredient in FINTEPLA), and valvular heart disease (VHD) and pulmonary arterial hypertension (PAH), cardiac monitoring via echocardiogram is required prior to starting treatment, during treatment, and after treatment with FINTEPLA concludes. Cardiac monitoring via echocardiogram can aid in early detection of these conditions. In clinical trials for DS and LGS of up to 3 years in duration, no patient receiving FINTEPLA developed VHD or PAH.

Monitoring: Prior to starting treatment, patients must undergo an echocardiogram to evaluate for VHD and PAH. Echocardiograms should be repeated every 6 months, and once at 3-6 months post treatment with FINTEPLA.

The prescriber must consider the benefits versus the risks of initiating or continuing treatment with FINTEPLA if any of the following signs are observed via echocardiogram: valvular abnormality or new abnormality; VHD indicated by mild or greater aortic regurgitation or moderate or greater mitral regurgitation, with additional characteristics of VHD (eg, valve thickening or restrictive valve motion); PAH indicated by elevated right heart/pulmonary artery pressure (PASP >35mmHg).

FINTEPLA REMS Program (see Boxed Warning): FINTEPLA is available only through a restricted distribution program called the FINTEPLA Risk Evaluation and Mitigation Strategy (REMS) Program. Prescribers must be certified by enrolling in the FINTEPLA REMS. Prescribers must counsel patients receiving FINTEPLA about the risk of valvular heart disease and pulmonary arterial hypertension, how to recognize signs and symptoms of valvular heart disease and pulmonary arterial hypertension, the need for baseline (pretreatment) and periodic cardiac monitoring via echocardiogram during FINTEPLA treatment, and cardiac monitoring after FINTEPLA treatment. Patients must enroll in the FINTEPLA REMS and comply with ongoing monitoring requirements. The pharmacy must be certified by enrolling in the FINTEPLA REMS and must only dispense to patients who are authorized to receive FINTEPLA. Wholesalers and distributors must only distribute to certified pharmacies. Further information is available at www.FinteplaREMS.com or by telephone at 1-877-964-3649.

Decreased Appetite and Decreased Weight: FINTEPLA can cause decreases in appetite and weight. Decreases in weight appear to be dose related. Approximately half of the patients with LGS and most patients with DS resumed the expected measured increases in weight during the open-label extension studies. Weight should be monitored regularly during treatment with FINTEPLA, and dose modifications should be considered if a decrease in weight is observed.

Somnolence, Sedation, and Lethargy: FINTEPLA can cause somnolence, sedation, and lethargy. Other central nervous system (CNS) depressants, including alcohol, could potentiate these effects of FINTEPLA. Prescribers should monitor patients for somnolence and sedation and should advise patients not to drive or operate machinery until they have gained sufficient experience on FINTEPLA to gauge whether it adversely affects their ability to drive or operate machinery.

Suicidal Behavior and Ideation: Antiepileptic drugs (AEDs), including FINTEPLA, increase the risk of suicidal thoughts or behaviors in patients taking these drugs for any indication. Patients treated with an AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behaviors, or any unusual changes in mood or behavior.

Anyone considering prescribing FINTEPLA or any other AED must balance the risk of suicidal thoughts or behaviors with the risks of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behaviors. Should suicidal thoughts and behaviors emerge during treatment, consider whether the emergence of these symptoms in any given patient may be related to the illness being treated.

Withdrawal of Antiepileptic Drugs: As with most AEDs, FINTEPLA should generally be withdrawn gradually because of the risk of increased seizure frequency and status epilepticus. If withdrawal is needed because of a serious adverse reaction, rapid discontinuation can be considered.

Serotonin Syndrome: Serotonin syndrome, a potentially life-threatening condition, may occur with FINTEPLA, particularly during concomitant administration of FINTEPLA with other serotonergic drugs, including, but not limited to, selective serotonin-norepinephrine reuptake inhibitors (SNRIs), selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), bupropion, triptans, dietary supplements (eg, St. John's Wort, tryptophan), drugs that impair metabolism of serotonin (including monoamine oxidase inhibitors [MAOIs], which are contraindicated with FINTEPLA), dextromethorphan, lithium, tramadol, and antipsychotics with serotonergic agonist activity. Patients should be monitored for the emergence of signs and symptoms of serotonin syndrome, which include mental status changes (eg, agitation, hallucinations, coma), autonomic instability (eg, tachycardia, labile blood pressure, hyperthermia), neuromuscular signs (eg, hyperreflexia, incoordination), and/or gastrointestinal symptoms (eg, nausea, vomiting, diarrhea). If serotonin syndrome is suspected, treatment with FINTEPLA should be stopped immediately and symptomatic treatment should be started.

Increase in Blood Pressure: FINTEPLA can cause an increase in blood pressure. Rare cases of significant elevation in blood pressure, including hypertensive crisis, has been reported in adult patients treated with fenfluramine, including patients without a history of hypertension. In clinical trials for DS and LGS of up to 3 years in duration, no pediatric or adult patient receiving FINTEPLA developed hypertensive crisis. Monitor blood pressure in patients treated with FINTEPLA.

Glaucoma: Fenfluramine can cause mydriasis and can precipitate angle closure glaucoma. Consider discontinuing treatment with FINTEPLA in patients with acute decreases in visual acuity or ocular pain.


The most common adverse reactions observed in DS studies (incidence at least 10% and greater than placebo) were decreased appetite; somnolence, sedation, lethargy; diarrhea; constipation; abnormal echocardiogram; fatigue, malaise, asthenia; ataxia, balance disorder, gait disturbance; blood pressure increased; drooling, salivary hypersecretion; pyrexia; upper respiratory tract infection; vomiting; decreased weight; fall; status epilepticus.

The most common adverse reactions observed in the LGS study (incidence at least 10% and greater than placebo) were diarrhea; decreased appetite; fatigue; somnolence; vomiting.


Strong CYP1A2, CYP2B6, or CYP3A Inducers: Coadministration with strong CYP1A2, CYP2B6, or CYP3A inducers will decrease fenfluramine plasma concentrations. If coadministration of a strong CYP1A2, CYP2B6, or CYP3A inducer with FINTEPLA is necessary, monitor the patient for reduced efficacy and consider increasing the dosage of FINTEPLA as needed. If a strong CYP1A2, CYP2B6, or CYP3A inducer is discontinued during maintenance treatment with FINTEPLA, consider gradual reduction in the FINTEPLA dosage to the dose administered prior to initiating the inducer.

Strong CYP1A2 or CYP2D6 Inhibitors: Coadministration with strong CYP1A2 or CYP2D6 inhibitors will increase fenfluramine plasma concentrations. If FINTEPLA is coadministered with strong CYP1A2 or CYP2D6 inhibitors, the maximum daily dosage of FINTEPLA is 20 mg. If a strong CYP1A2 or CYP2D6 inhibitor is discontinued during maintenance treatment with FINTEPLA, consider gradual increase in the FINTEPLA dosage to the dose recommended without CYP1A2 or CYP2D6 inhibitors. If FINTEPLA is coadministered with stiripentol and a strong CYP1A2 or CYP2D6 inhibitor, the maximum daily dosage of FINTEPLA is 17 mg.


Administration to patients with hepatic impairment is not recommended.

To report SUSPECTED ADVERSE REACTIONS, contact Zogenix Inc. at 1-866-964-3649 (1-866-Zogenix) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Please see full Prescribing Information, including Boxed Warning, for additional important information on FINTEPLA.


For further information, contact UCB: 

Investor Relations
Antje Witte
T +32.2.559.9414

Corporate Communications
Erica Puntel, U.S. Media Relations
T +404 938 5359

Laurent Schots, Media Relations

Nick Francis
T +44 7769 307745

About UCB
UCB, Brussels, Belgium (www.ucb.com) is a global biopharmaceutical company focused on the discovery and development of innovative medicines and solutions to transform the lives of people living with severe diseases of the immune system or of the central nervous system. With approximately 8 600 people in approximately 40 countries, the company generated revenue of € 5.8 billion in 2021. UCB is listed on Euronext Brussels (symbol: UCB). Follow us on Twitter: @UCB_news.

Forward looking statements 
This press release contains forward-looking statements including, without limitation, statements containing the words “believes”, “anticipates”, “expects”, “intends”, “plans”, “seeks”, “estimates”, “may”, “will”, “continue” and similar expressions. These forward-looking statements are based on current plans, estimates and beliefs of management. All statements, other than statements of historical facts, are statements that could be deemed forward-looking statements, including but not limited to, the ability of UCB to successfully integrate the operations of Zogenix as planned or at all, estimates of revenues, operating margins, capital expenditures, cash, other financial information, expected legal, arbitration, political, regulatory or clinical results or practices and other such estimates and results. By their nature, such forward-looking statements are not guarantees of future performance and are subject to known and unknown risks, uncertainties and assumptions which might cause the actual results, financial condition, performance or achievements of UCB, or industry results, to differ materially from those that may be expressed or implied by such forward-looking statements contained in this press release. Important factors that could result in such differences include: the global spread and impact of COVID-19, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws, and hiring and retention of its employees. There is no guarantee that new product candidates will be discovered or identified in the pipeline, or that new indications for existing products will be developed and approved. Movement from concept to commercial product is uncertain; preclinical results do not guarantee safety and efficacy of product candidates in humans. So far, the complexity of the human body cannot be reproduced in computer models, cell culture systems or animal models. The length of the timing to complete clinical trials and to get regulatory approval for product marketing has varied in the past and UCB expects similar unpredictability going forward. Products or potential products which are the subject of partnerships, joint ventures or licensing collaborations may be subject to disputes between the partners or may prove to be not as safe, effective or commercially successful as UCB may have believed at the start of such partnership. UCB’ efforts to acquire other products or companies and to integrate the operations of such acquired companies may not be as successful as UCB may have believed at the moment of acquisition. Also, UCB or others could discover safety, side effects or manufacturing problems with its products and/or devices after they are marketed. The discovery of significant problems with a product similar to one of UCB’s products that implicate an entire class of products may have a material adverse effect on sales of the entire class of affected products. Moreover, sales may be impacted by international and domestic trends toward managed care and health care cost containment, including pricing pressure, political and public scrutiny, customer and prescriber patterns or practices, and the reimbursement policies imposed by third-party payers as well as legislation affecting biopharmaceutical pricing and reimbursement activities and outcomes. Finally, a breakdown, cyberattack or information security breach could compromise the confidentiality, integrity and availability of UCB’s data and systems.

Given these uncertainties, you should not place undue reliance on any of such forward-looking statements. There can be no guarantee that the investigational or approved products described in this press release will be submitted or approved for sale or for any additional indications or labelling in any market, or at any particular time, nor can there be any guarantee that such products will be or will continue to be commercially successful in the future.

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  1. Knupp K, Scheffer, I, et al. Efficacy and Safety of Fenfluramine for the Treatment of Seizures Associated with Lennox-Gastaut Syndrome: A Randomized Clinical Study. JAMA Neurology. 2022; E1-E11.
  2. Strzelczyk A, Schubert-Bast S. Expanding the Treatment Landscape for Lennox-Gastaut Syndrome: Current and Future Strategies. CNS Drugs. 2021;35(1):61-83. 
  3. Arzimanoglou A, French J, Blume WT, et al. Lennox-Gastaut syndrome: a consensus approach on diagnosis, assessment, management, and trial methodology. Lancet Neurol. 2009;8(1):82-93.
  4. Sveinsson O, Andersson T, Mattsson P, Carlsson S, Tomson T. Clinical risk factors in SUDEP: A nationwide population-based case-control study. Neurology. 2020;94(4):e419-e429.
  5. FINTEPLA® (fenfluramine) oral solution CIV. U.S. Prescribing Information. March 2022.
  6. Mastrangelo M. Lennox-Gastaut Syndrome: A State of the Art Review. Neuropediatrics. 2017;48(3):143-151.
  7. LGS Foundation. LGS Characteristics and Major Concerns Survey. https://www.lgsfoundation.org/wp-content/uploads/2021/08/2019-PFDD-Caregiver-Survey-1.pdf. Accessed March 2022.
  8. Data on file, Zogenix, Inc. 2021.
  9. Cross JH, Auvin S, Falip M, Striano P, Arzimanoglou A. Expert opinion on the management of Lennox-Gastaut syndrome: treatment algorithms and practical considerations. Front Neurol.  2017;8:505.
  10. Gastaut H, Roger J, Soulayrol R, et al. Childhood epileptic encephalopathy with diffuse slow spike-waves (otherwise known as "petit mal variant") or Lennox syndrome. Epilepsia. 1966;7(2):139-179.
  11. Cross JH, Galer BS, Gil-Nagel A, et al. Impact of fenfluramine on the expected SUDEP mortality rates in patients with Dravet syndrome. Seizure. 2021;93:154-159.
  12. FINTEPLA Summary of Product Characteristics. January 2022.
  13. Zogenix Press Release. Zogenix Submits New Drug Application for FINTEPLA® (Fenfluramine) in Japan for the Treatment of Epileptic Seizures Associated with Dravet Syndrome. 21 December 2021.
  14. Zogenix Press Release. Zogenix Submits Type II Variation Application to the European Medicines Agency (EMA) to Expand the Use of FINTEPLA® (fenfluramine) for the Treatment of Seizures Associated with Lennox-Gastaut Syndrome. 20 December 2021.


FINTEPLA® and Zogenix, Inc. are registered trademarks of the UCB Group of Companies.
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