- Phase 3 study met primary and most key secondary clinical endpoints
- This marks the third developmental and epileptic encephalopathies (DEE) population for fenfluramine with positive phase 3 results
- Results underscore the impact of UCB’s continued investment in scientific innovation to advance new treatments for DEEs
- CDKL5 deficiency disorder (CDD) is an ultra-rare, severe DEE with an onset in early infancy with a high unmet need, and has limited treatment options
- CDD affects approximately 1 in 40,000 to 60,000 live births, with a median age of onset of six weeks1,2
- UCB plans to submit for regulatory approval to bring this potential treatment option to people living with CDD as soon as possible
ATLANTA, GA, USA I June 27, 2025 I UCB, a global biopharmaceutical company, today announced that the Phase 3 study investigating the safety and efficacy of adjunctive fenfluramine in CDKL5 deficiency disorder (CDD) met its primary and most key secondary endpoints.3 The study is a randomized, double-blind, placebo-controlled, fixed-dose, multi-center study examining the efficacy and safety of adjunctive fenfluramine treatment in 87 individuals aged one through 35, with a CDD diagnosis and uncontrolled seizures.4
“These results pave the way for creating significant therapeutic progress and represent an important milestone in UCB’s mission to bring meaningful innovation to individuals and families affected by developmental and epileptic encephalopathies (DEEs). We are grateful to the patients, families, and researchers who made this progress possible, and we look forward to working with the health authorities to make treatment available as soon as possible,” said Fiona du Monceau, Executive Vice President, Patient Evidence, UCB.
The primary endpoint of the study is based on the median percent change in countable motor seizure frequency (CMSF) between baseline and the titration plus maintenance phase, comparing fenfluramine with the placebo group.3 Full results will be presented at an upcoming scientific meeting.
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.1 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.2
In the study, fenfluramine was generally well tolerated, and the safety profile was consistent with previous studies in DS/LGS.3 UCB is currently conducting an open-label, flexible-dose, long-term 54-week extension phase of the study to characterize the long-term safety and tolerability of fenfluramine in pediatric and adult individuals with CDD.4
In the United States, fenfluramine oral solution is indicated for the treatment of seizures associated with Dravet syndrome and Lennox-Gastaut syndrome in patients 2 years of age and older.5 It is not approved for use in CDD by any regulatory authority worldwide.
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 9,000 people in approximately 40 countries, the company generated revenue of € 6.15 billion in 2024. UCB is listed on Euronext Brussels (symbol: UCB). Follow us on Twitter: @UCB_news.
References
1 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.
2 Overview of Medical-scientific Research in the Netherlands (OMON). A Phase 3, Randomized, Double-Blind, Placebo-Controlled, Fixed-Dose, Multicenter Study to Examine the Efficacy and Safety of ZX008 in Subjects with CDKL5 Deficiency Disorder Followed by an Open-Label Extension. 2022. Available at: https://onderzoekmetmensen.nl/en/node/56446/pdf. Accessed: June 2025.
3 UCB data on file. 2025
4 ClinicalTrials.gov. NCT05064878. Available at: https://clinicaltrials.gov/study/NCT05064878. Accessed: June 2025.
5 FINTEPLA (fenfluramine) U.S. prescribing information. Smyrna, GA: UCB, Inc. https://www.ucb-usa.com/fintepla-prescribing-information.pdf. Accessed June 2025.
SOURCE: UCB
Post Views: 1,581
- Phase 3 study met primary and most key secondary clinical endpoints
- This marks the third developmental and epileptic encephalopathies (DEE) population for fenfluramine with positive phase 3 results
- Results underscore the impact of UCB’s continued investment in scientific innovation to advance new treatments for DEEs
- CDKL5 deficiency disorder (CDD) is an ultra-rare, severe DEE with an onset in early infancy with a high unmet need, and has limited treatment options
- CDD affects approximately 1 in 40,000 to 60,000 live births, with a median age of onset of six weeks1,2
- UCB plans to submit for regulatory approval to bring this potential treatment option to people living with CDD as soon as possible
ATLANTA, GA, USA I June 27, 2025 I UCB, a global biopharmaceutical company, today announced that the Phase 3 study investigating the safety and efficacy of adjunctive fenfluramine in CDKL5 deficiency disorder (CDD) met its primary and most key secondary endpoints.3 The study is a randomized, double-blind, placebo-controlled, fixed-dose, multi-center study examining the efficacy and safety of adjunctive fenfluramine treatment in 87 individuals aged one through 35, with a CDD diagnosis and uncontrolled seizures.4
“These results pave the way for creating significant therapeutic progress and represent an important milestone in UCB’s mission to bring meaningful innovation to individuals and families affected by developmental and epileptic encephalopathies (DEEs). We are grateful to the patients, families, and researchers who made this progress possible, and we look forward to working with the health authorities to make treatment available as soon as possible,” said Fiona du Monceau, Executive Vice President, Patient Evidence, UCB.
The primary endpoint of the study is based on the median percent change in countable motor seizure frequency (CMSF) between baseline and the titration plus maintenance phase, comparing fenfluramine with the placebo group.3 Full results will be presented at an upcoming scientific meeting.
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.1 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.2
In the study, fenfluramine was generally well tolerated, and the safety profile was consistent with previous studies in DS/LGS.3 UCB is currently conducting an open-label, flexible-dose, long-term 54-week extension phase of the study to characterize the long-term safety and tolerability of fenfluramine in pediatric and adult individuals with CDD.4
In the United States, fenfluramine oral solution is indicated for the treatment of seizures associated with Dravet syndrome and Lennox-Gastaut syndrome in patients 2 years of age and older.5 It is not approved for use in CDD by any regulatory authority worldwide.
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 9,000 people in approximately 40 countries, the company generated revenue of € 6.15 billion in 2024. UCB is listed on Euronext Brussels (symbol: UCB). Follow us on Twitter: @UCB_news.
References
1 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.
2 Overview of Medical-scientific Research in the Netherlands (OMON). A Phase 3, Randomized, Double-Blind, Placebo-Controlled, Fixed-Dose, Multicenter Study to Examine the Efficacy and Safety of ZX008 in Subjects with CDKL5 Deficiency Disorder Followed by an Open-Label Extension. 2022. Available at: https://onderzoekmetmensen.nl/en/node/56446/pdf. Accessed: June 2025.
3 UCB data on file. 2025
4 ClinicalTrials.gov. NCT05064878. Available at: https://clinicaltrials.gov/study/NCT05064878. Accessed: June 2025.
5 FINTEPLA (fenfluramine) U.S. prescribing information. Smyrna, GA: UCB, Inc. https://www.ucb-usa.com/fintepla-prescribing-information.pdf. Accessed June 2025.
SOURCE: UCB
Post Views: 1,581
