UCB presents data at EEC 2026 highlighting continued leadership in epilepsy and developmental and epileptic encephalopathies

Brussels, Belgium - 1 September 2026 – 7:00 (CET) - UCB (Euronext Brussels: UCB), a global biopharmaceutical company, is presenting 18 abstracts in total at the 16th European Epilepsy Congress (EEC), Athens, Greece, September 5-9, 2026. The research presented spans multiple developmental and epileptic encephalopathies (DEEs),^2,3,4,5,9,10 neurodevelopmental disorder Rett syndrome⁶, alongside patient-focused research into acute seizure management^7,8, and policy analysis of transition from pediatric to adult care in Europe and the U.S.⁹

Donatello Crocetta, Chief Medical Officer at UCB, said: “For decades, UCB has been committed to advancing care for people living with epilepsy through meaningful scientific innovation. The data we are presenting at EEC deepen our understanding of outcomes that matter most to individuals and families affected by developmental and epileptic encephalopathies (DEEs) and epileptic syndromes. Together with our recent acquisition of Neurona Therapeutics,¹¹ these insights reflect our ambition to shape the future of epilepsy care through both continued innovation and the exploration of next-generation therapeutic approaches.”

Broader impact beyond seizures

• In adults with Lennox-Gastaut syndrome (LGS), a post hoc analysis of a randomized controlled trial (n=67) and its open-label extension (n=41) showed that fenfluramine was associated with improvements in behavioral regulation and everyday executive functioning, based on caregiver-completed Behavior Rating Inventory of Executive Functioning^®-Adult Version (BRIEF^®-A) assessments. Clinically meaningful improvement was defined as a Reliable Change Index ≥90% on BRIEF^®-A T-scores. During the randomized controlled trial, a greater percentage of adults treated with fenfluramine (0.7 mg/kg/day, n=18; 0.2 mg/kg/day, n=24) experienced clinically meaningful improvements versus placebo (n=25) on caregiver-completed measures of behavioral regulation (17%–33% vs 12%), metacognition (33% vs 4%), and global executive composite (28%–38% vs 8%).²
• In a prospective evaluation of non-seizure outcomes in Dravet syndrome (DS), 10 patients, 5 pediatric (4–17 years) and 5 adults (24–46 years), were assessed before fenfluramine treatment initiation and after one year. Among patients treated for more than 6 months, pediatric patients experienced a generalized tonic-clonic seizure (GTCS) reduction of 25% and 100% (n=2; median 62.5%), while adults achieved a median GTCS reduction of 74.5% (n=3; range 69-80%). Of the 3 patients who had reached 1-year follow-up, no statistically significant improvements in non-seizure outcomes were detected. However, caregivers reported improvements in motor function, alertness, and daily living skills.³

UCB's pipeline developments

Seizure control in CDKL5 deficiency disorder (CDD)

• A post hoc analysis from a Phase 3 randomized, double-blind, placebo-controlled trial (n=86; 14 weeks) showed that fenfluramine was associated with an increase in countable motor seizure-free days compared with placebo.⁴ Patients treated with fenfluramine experienced a median gain of 6.4 countable motor seizure (CMS)-free days per month versus 0.1 day per month with placebo, and a higher proportion achieved more than 7 CMS-free days per month (71.4% vs 31.8%).⁴ Among fenfluramine-treated patients, those who gained ≥7 CMS-free days per month were more likely to be rated by investigators as "much improved" or "very much improved" on the Clinical Global Impression-Improvement (CGI-I) scale than non-responders (57.9% vs 21.7%).⁴
• A separate post hoc time-to-event analysis evaluated the time to return to baseline seizure counts in children and adults living with CDD.⁵ Individuals on fenfluramine took longer to reach their baseline seizure counts compared with placebo (CMS: 55 vs 29 days, respectively; all seizures: 51 vs 29 days, respectively).⁵ 

Rett syndrome

• UCB presents the design of an ongoing Phase 3 randomized, double-blind, placebo-controlled study with an open-label extension (n=200) evaluating the efficacy and safety profile of fenfluramine in addressing a range of symptoms experienced by patients living with Rett syndrome, a severe developmental disorder with significant unmet medical needs.⁶
• Coprimary efficacy endpoints include change from baseline to week 14 in caregiver-completed Rett Syndrome Behaviour Questionnaire total score and investigator-completed Clinical Global Impression of Change score. Secondary efficacy endpoints assess sleep (PROMIS Sleep Disturbance score), communication (Observer-Reported Communication Ability score) and Caregiver Global Impression of Change-seizure score at Week 14.⁶

Emerging need for faster seizure control

• Patient and caregiver preference studies highlighted unmet need in acute seizure management. Findings from a quantitative survey (n=374) and qualitative interviews (n=53) conducted across France/Italy/Poland/Spain/UK/US showed that awareness of the Rapid and Early Seizure Termination (REST) approach is low (15%; 8 out of 53 participants), although 67% (30 out of 45 participants not currently following REST approach) considered it feasible once explained.^7,8 The most important treatment attributes identified were time to seizure cessation (32.4%) and mode of administration (26.6%).⁸ Participants preferred fast-acting, non-rectal options, and in a willingness-to-wait exercise, 88% (328 out of 374 participants) indicated they would be willing to wait 30 seconds to administer treatment, supporting the feasibility of early intervention.⁸

Adults living with DEEs

• A policy analysis assessing transition from pediatric to adult care for patients with rare and complex epilepsies across Europe (UK, France, Spain, Italy, Germany) and the United States identified persistent gaps, including fragmented pathways, limited multidisciplinary support, and a lack of structured protocols. Approximately 50% of 57 respondents in an EpiCare reference network survey reported having no written transition protocol, while only 12% provided dedicated transition coordinators and physical spaces. These findings highlighted the need for structured, multidisciplinary transition pathways to improve continuity of care and patient outcomes.⁹
• An internet-based anonymous survey (n=582) found that caregivers to individuals living with DEEs who are over 16 years (n=166) reported that disruptive seizures, sleep, and/or behavior were common and associated with temporary reduced abilities to perform one or more activities of daily living (ADLs) and to communicate.¹⁰

Expressing epilepsy exhibition

UCB will present the first art exhibition at the European Epilepsy Congress (EEC) on September 6 and 7. Titled Expressing Epilepsy, the global initiative features artworks created by people living with epilepsy. Through visual representations of seizure patterns and lived experiences, the exhibition aims to raise awareness, foster understanding, and highlight the broader impact of epilepsy beyond seizures. The exhibition will be held at Alexandra Trianti Foyer.

Symposium

UCB will host a scientific symposium on 7 September, 14:00 - 15:00 EEST, entitled “The Ripple Effect: How Small Changes Transform the Management of Patients with DEEs”.

In the European Union (EU), fenfluramine is approved for the treatment of seizures associated with Dravet syndrome and Lennox-Gastaut syndrome as an add-on therapy to other anti-epileptic medicines for patients 2 years of age and older.¹ Fenfluramine is not approved for use in CDKL5 deficiency disorder (CDD) or Rett syndrome by any regulatory authority worldwide.¹

For further information, contact UCB: 

Global Communications
Anna Clark
T +44.73.8.668.67.79
anna.clark@ucb.com 

Corporate Communications, Media Relations
Laurent Schots
T +32.2.559.92.64
laurent.schots@ucb.com

Investor Relations
Yvonne Naughton
T +44.175.344.7521
yvonne.naughton@ucb.com

Sahar Yazdian
T +32.2.559.94.37
sahar.yazdian@ucb.com

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 more than 9000 people in approximately 40 countries, the company generated revenue of € 7.7 billion in 2025. UCB is listed on Euronext Brussels (symbol: UCB).

About CDD

CDKL5 deficiency disorder (CDD) is an ultra-rare DEE with refractory infantile-onset epilepsy and severe global neurodevelopmental delays resulting in intellectual, motor, cortical visual, and sleep impairments as major features. It is caused by pathogenic variants in the Cyclin Dependent Kinase-like 5 (CDKL5) gene located on the X chromosome. It is estimated that CDD affects approximately 1 in 40,000 to 60,000 live births, with a median age of onset of six weeks) 

Forward looking statements
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Important Safety Information about FINTEPLA▼ (fenfluramine) in the EU¹

Indications: Treatment of seizures associated with Dravet syndrome and Lennox-Gastaut syndrome as an add-on therapy to other anti-epileptic medicines for patients 2 years of age and older. Dosage and Administration: Please refer to SmPC for full information. Should be initiated and supervised by physicians with experience in the treatment of epilepsy. Fintepla is prescribed and dispensed according to the Fintepla controlled access programme. Patients who are not taking stiripentol: Starting dose is 0.1 mg/kg twice daily. After 7 days, if tolerated, can increase dose to 0.2 mg/kg twice daily. After an additional 7 days, in patients with Dravet syndrome, if tolerated and further seizure reduction required, can increase dose to a maximum of 0.35 mg/kg twice daily; in patients with Lennox-Gastaut syndrome, dosage should be increased as tolerated to a maximum of 0.35 mg/kg twice daily, which is the recommended maintenance dose. Patients requiring more rapid titration may increase the dose every 4 days. Do not exceed maximum daily dose of 26 mg (13 mg twice daily, 6.0 ml twice daily). Patients who are taking stiripentol: Starting dose is 0.1 mg/kg twice daily. After 7 days, if tolerated, can increase dose to 0.2 mg/kg twice daily, which is the recommended maintenance dose. Patients requiring more rapid titration may increase the dose every 4 days. Do not exceed a total dose of 17 mg (8.6 mg twice daily, 4.0 ml twice daily). To calculate the dose volume up to the maximal recommended dose, you must use the formula: Weight (kg) x Weight-based dosage (mg/kg) ÷ 2.2 mg/ml = ml dose to be taken twice daily. The calculated dose should always be rounded up or down to the nearest graduation mark, following standard rounding conventions. Discontinuation: When discontinuing treatment, decrease the dose gradually. As with all anti-epileptic medicines, avoid abrupt discontinuation when possible to minimize the risk of increased seizure frequency and status epilepticus. A final echocardiogram should be conducted 3-6 months after the last dose of treatment with fenfluramine. Renal impairment: Generally, no dose adjustment is recommended when administered to patients with mild to severe renal impairment, however, a slower titration may be considered. If adverse reactions are reported, a dose reduction may be needed. Has not been studied in patients with end-stage renal disease. Not known if fenfluramine or its active metabolite, norfenfluramine, is dialyzable. There are no specific clinical data on the use of Fintepla with stiripentol in patients with impaired renal function, therefore Fintepla is not recommended for use in patients with impaired renal function treated with stiripentol. Hepatic impairment: Generally, no dose adjustment is recommended when Fintepla is administered without concomitant stiripentol to patients with mild and moderate hepatic impairment (Child-Pugh Class A and B). In patients with severe hepatic impairment (Child-Pugh C) not receiving concomitant stiripentol, the maximum dosage is 0.2mg/kg twice daily, and the maximal total daily dose is 17 mg. There are limited clinical data on the use of Fintepla with stiripentol in patients with mild impaired hepatic function. A slower titration may be considered in patients with hepatic impairment and a dose reduction may be needed if adverse reactions are reported. No clinical data is available on the use of Fintepla with stiripentol in moderate and severe hepatic impairment, therefore not recommended for use. Elderly: No data available. Paediatric population: Safety and efficacy in children below 2 years of age not yet established. No data available.  Contraindications: Hypersensitivity to active substance or any excipients. Aortic or mitral valvular heart disease and pulmonary arterial hypertension. Within 14 days of the administration of monoamine oxidase inhibitors due to an increased risk of serotonin syndrome. Warnings and Precautions: Aortic or mitral valvular heart disease and pulmonary arterial hypertension: Fenfluramine can cause valvular heart disease and pulmonary arterial hypertension in patients treated for Dravet syndrome or Lennox-Gastaut syndrome (see section 4.8 of the SmPC). Therefore, echocardiographic monitoring must be performed.Prior to starting treatment, patients must undergo an echocardiogram to establish a baseline and exclude any pre-existing valvular heart disease or pulmonary hypertension. Conduct echocardiogram monitoring every 6 months for the first 2 years and annually thereafter. Once treatment is discontinued for any reasons, a final echocardiogram should be conducted 3-6 months after the last dose of treatment with fenfluramine. If an echocardiogram indicates pathological valvular changes, consider follow-up earlier to evaluate whether the abnormality is persistent. If pathological abnormalities seen on echocardiogram, evaluate the benefit versus risk of continuing fenfluramine treatment with the prescriber, caregiver and cardiologist. If treatment is stopped because of aortic or mitral valvular heart disease, appropriate monitoring and follow-up should be provided in accordance with local guidelines for the treatment of aortic or mitral valvular heart disease. If echocardiogram findings suggestive of pulmonary arterial hypertension, perform a repeat echocardiogram as soon as possible and within 3 months to confirm these findings. If echocardiogram finding is confirmed suggestive of an increased probability of pulmonary arterial hypertension defined as intermediate probability, conduct a benefit-risk evaluation of continuation of Fintepla by the prescriber, carer and cardiologist. If echocardiogram suggests a high probability, it is recommended fenfluramine treatment should be stopped. Decreased appetite and weight loss: Fenfluramine can cause decreased appetite and weight loss - an additive effect can occur in combination with other anti-epileptic medicines such as stiripentol. Monitor the patient’s weight. Undertake risk-benefit evaluation before starting treatment if history of anorexia nervosa or bulimia nervosa. Fintepla controlled access programme: A controlled access programme has been created to 1) prevent offlabel use in weight management in obese patients and 2) confirm that prescribing physicians have been informed of the need for periodic cardiac monitoring in patients taking Fintepla. Somnolence: Fenfluramine can cause somnolence which could be potentiated by other central nervous system depressants. Suicidal behaviour and ideation: Suicidal behaviour and ideation have been reported in patients treated with anti-epileptic medicines in several indications. Advise patients and caregivers to seek medical advice should any signs of suicidal behaviour and ideation emerge. Serotonin syndrome: Serotonin syndrome, a potentially life-threatening condition, may occur with fenfluramine treatment, particularly with concomitant use of other serotonergic agents; with agents that impair metabolism of serotonin such as MAOIs; or with antipsychotics that may affect the serotonergic neurotransmitter systems. Carefully observe the patient, particularly during treatment initiation and dose increases. If serotonin syndrome is suspected, a dose reduction or discontinuation of therapy with Fintepla and/or other serotonergic agents should be considered. Increased seizure frequency: A clinically relevant increase in seizure frequency may occur during treatment, which may require adjustment in the dose of fenfluramine and/or concomitant anti-epileptic medicines, or discontinuation of fenfluramine, should the benefit-risk be negative. Cyproheptadine: Cyproheptadine is a potent serotonin receptor antagonist and may therefore decrease the efficacy of fenfluramine. If cyproheptadine is added to treatment with fenfluramine, monitor patient for worsening of seizures. If fenfluramine treatment is initiated in a patient taking cyproheptadine, fenfluramine’s efficacy may be reduced. Glaucoma: Fenfluramine can cause mydriasis and can precipitate angle closure glaucoma. Discontinue therapy in patients with acute decreases in visual acuity. Consider discontinuation if ocular pain of unknown origin. Effect of CYP1A2 or CYP2B6 inducers: Co-administration with strong CYP1A2 inducers or CYP2B6 inducers will decrease fenfluramine plasma concentrations, which may lower the efficacy of fenfluramine. If co-administration is considered necessary, the patient should be monitored for reduced efficacy and a dose increase of fenfluramine could be considered provided that it does not exceed twice the maximum daily dose (52 mg/day). If a strong CYP1A2 or CYP2B6 inducer is discontinued during maintenance treatment with fenfluramine, consider gradual reduction of the fenfluramine dosage to the dose administered prior to initiating the inducer. Effect of CYP1A2 or CYP2D6 inhibitors: Initiation of concomitant treatment with a strong CYP1A2 or CYP2D6 inhibitor may result in higher exposure and, therefore, adverse events should be monitored, and a dose reduction may be needed in some patients. Excipients: Contains sodium ethyl para-hydroxybenzoate (E 215) and sodium methyl para-hydroxybenzoate (E 219) - may cause allergic reactions (possibly delayed). It also contains sulfur dioxide (E 220) which may rarely cause severe hypersensitivity reactions and bronchospasm. Patients with rare glucose-galactose malabsorption should not take this medicine. The product contains less than 1 mmol sodium (23 mg) per the maximum daily dose of 12 mL; essentially ‘sodium-free’. Contains glucose - may be harmful to teeth. Interactions: Pharmacodynamic interactions with other CNS depressants increase the risk of aggravated central nervous system depression. An increase in dose may be necessary when coadministered with rifampicin or a strong CYP1A2 or CYP2B6 inducer. In in vitro studies co-administration with a strong CYP1A2 or CYP2D6 inhibitor may result in higher exposure (see section 4.4 of the SmPC). Co-administration with CYP2D6 substrates or MATE1 substrates may increase their plasma concentrations. Co-administration with CYP2B6 or CYP3A4 substrates may decrease their plasma concentrations. Pregnancy and lactation: Limited data in pregnant women. As a precaution, avoid use of Fintepla in pregnancy. It is unknown whether fenfluramine/metabolites are excreted in human milk. Animal data have shown excretion of fenfluramine/metabolites in milk. A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from Fintepla taking into account the benefit of breast-feeding for the child and the benefit of therapy for the woman. Drive and use machines.: Fintepla has moderate influence on the ability to drive/ use machines as it may cause somnolence and fatigue. Advise patients not to drive or operate machinery until they have sufficient experience to gauge whether it adversely affects their abilities.  
Adverse effects: Very common (≥1/10): Decreased appetite, somnolence, diarrhoea, fatigue. Common (≥1/100 to <1/10): Bronchitis, abnormal behaviour, aggression, agitation, insomnia, mood swings, ataxia, hypotonia, lethargy, seizure, status epilepticus, tremor, constipation, salivary hypersecretion, vomiting, rash, weight decreased, blood glucose decreased, and blood prolactin increased. Not known (frequency cannot be estimated from the available data): Irritability, serotonin syndrome, valvular heart disease, and pulmonary arterial hypertension.. Refer to SmPC for other adverse reactions. 

▼ This medicinal product is subject to additional monitoring. This will allow quick identification of new safety information. Healthcare professionals are asked to report any suspected adverse reactions. 

Refer to the European Summary of Product Characteristics for other adverse reactions and full Prescribing Information. https://www.ema.europa.eu/en/documents/product-information/fintepla-epar-product-information_en.pdf

References

1. FINTEPLA^® EU SmPC. Available at: https://www.ema.europa.eu/en/documents/product-information/fintepla-epar-product-information_en.pdf. Accessed: August 2026.
2. Breuillard D, et al. 2026. EEC. Poster P0275.
3. Gjerulfsen CE, et al. 2026. EEC. Poster P0245.
4. Aledo-Serrano A, et al. EEC. Poster P0235.
5. Marsh E, et al. 2026. EEC. Poster P0238.
6. González-Alguacil E, et al. 2026. EEC. Poster P0328.
7. Ho K A, et al. 2026. EEC. Abstract P0312. 
8. Laloyaux C, et al. 2026. EEC. Abstract P0313.
9. Wierzbicka N, et al. 2026. EEC. Poster P0870.
10. Wilkinson A, et al. 2026. EEC. Poster P0957.
11. UCB. UCB completes acquisition of Neurona Therapeutics, advancing its leadership as innovator in epilepsy through regenerative science. https://www.ucb.com/newsroom/press-releases/article/ucb-completes-acquisition-of-neurona-therapeutics-advancing-its-leadership-as-innovator-in-epilepsy-through-regenerative-science Accessed: 7 August 2026.
12. Zuberi, et al. ILAE classification and definition of epilepsy syndromes with onset in neonates and infants: Position statement by the ILAE Task Force on Nosology and Definitions. Epilepsia. 2022;63(6):1349-97.