UCB plans to file for regulatory approval of Fintepla to treat a third epileptic condition “as soon as possible,” the company said, as it reported results of a phase 3 trial in patients with the ultra-rare cyclin-dependent kinase-like-5 (CDKL5) deficiency disorder.
The study of 87 patients aged 1 to 35 with CDKL5 achieved its primary endpoint, as Fintepla demonstrated a statistically significant reduction in seizures compared with placebo. The trial also achieved two of its three secondary objectives, the Brussels-based company said at the American Epilepsy Society (AES) conference in Atlanta.
Fintepla was first approved in 2020 to treat seizures associated with Dravet syndrome (DS), a rare, severe form of epilepsy that affects roughly 20,000 in the U.S. Two years later, Fintepla gained expansion into a larger epilepsy indication, Lennox-Gastaut syndrome (LGS), which affects approximately 48,000 in the U.S. In both indications, the cherry-flavored oral solution is cleared for patients age 2 and older.
CDKL5 is rarer still, affecting 1 out of 40,000 to 60,000 live births, and mostly women as the gene is located on the X chromosome, the company explained. The gene instructs the body how to make the CDKL5 protein, which is required for normal brain development. It is characterized by seizures that begin in infancy, followed by significant developmental delays, resulting in intellectual, motor, cortical visual, gastrointestinal and sleep impairments. The median age of seizure onset is six weeks.
“Families affected by this ultra-rare condition face immense daily challenges with frequent, treatment-resistant seizures that are profoundly disruptive to daily life,” Fiona du Monceau, UCB’s EVP, patient evidence, said in a release, adding that there is an “unmet need” in the indication.
In the trial, patients treated with Fintepla achieved a 47.6% reduction in countable motor seizure frequency (CMSF), compared to a 2.8% reduction for placebo. Additionally, 45% of those in the Fintepla arm realized at least a 50% reduction in CMSF compared with 4.5% of the patients who received placebo.
Fintepla also showed a clinically meaningful improvement versus placebo on the Clinical Global Impression-Improvement (CGI-I) scale, as investigators rated 38% of patients as “much improved” or “very much improved” compared to 7% of those on placebo at 14 weeks. Caregivers were more convinced of the positive effects of treatment, delivering CGI-I ratings of 52% for the Fintepla patients versus 2% for the placebo group.
Fintepla-treated patients saw an increase in countable motor seizure-free days. The median change from baseline in monthly frequency was 6.4 days in the Fintepla group compared with 0.1 day in the placebo group.
California-based Zogenix developed Fintepla and secured its original FDA approval. Two years later, UCB paid $1.9 billion to acquire the biotech months before the LGS approval. The deal was a strategic fit for UCB, which then had four epilepsy drugs on the market but was losing market exclusivity for the most successful one, Vimpat, a blockbuster that outsold the other three combined.
UCB reported Fintepla sales at 203 million euros ($236 million) for the first half of this year. The anti-convulsant medicine has generated increased sales over each of the previous four years and appears on track to exceed SVB Leerink’s $700 million projection for 2030 sales, upon its original approval five years ago.
The positive trial results add to the momentum for UCB, which saw a 41% boost in its market cap in the third quarter, which was the highest in the industry among top-20 companies. UCB is riding the launches of three key drugs approved in 2023—plaque psoriasis treatment Bimzelx and myasthenia gravis meds Rystiggo and Zilbrysq.