Fintepla open‑label extension shows sustained seizure reduction

Fintepla ® achieved a median 66.8% reduction in convulsive seizure frequency over a median 256‑day open‑label extension, confirming durable efficacy for Dravet syndrome and showing no cases of valvular heart disease or pulmonary hypertension【1】.

Efficacy across ages

The open‑label extension enrolled 232 patients who began fenfluramine at 0.2 mg kg⁻¹ day⁻¹, later titrating up to 0.7 mg kg⁻¹ day⁻¹ (or 0.4 mg kg⁻¹ day⁻¹ with stiripentol). Across the cohort, the median seizure frequency fell by 66.8% compared with double‑blind baseline, a statistically significant change (P < .001). Reductions were comparable between younger (<6 yr) and older (≥6 yr) participants, at 75.7% and 64.7% respectively, underscoring consistent benefit across the pediatric spectrum【1】.

Safety and tolerability

Adverse events were largely mild, with pyrexia (21.6%) and nasopharyngitis (19.4%) most common; appetite decrease was reported by 15.9% of patients. Crucially, no participants developed valvular heart disease or pulmonary arterial hypertension, addressing historic concerns linked to fenfluramine’s earlier appetite‑suppression use【1】.

Contextual relevance

These results extend earlier phase‑3 trials that showed 35‑50% of patients achieving ≥75% seizure reduction. The open‑label data reinforce the drug’s long‑term profile, offering clinicians a viable adjunctive option for a disorder where two‑thirds of patients typically require three or four antiepileptic drugs yet still experience frequent seizures【1】.

What to watch

• Regulatory filings: Any upcoming FDA or EMA submissions for fenfluramine in Dravet syndrome could affect market access.
• Long‑term cardiac monitoring: Ongoing echocardiography data will be key to confirming the absence of valvular effects over years.
• Real‑world uptake: Prescription trends in pediatric neurology clinics will indicate how quickly the therapy is adopted beyond trial settings.

The sustained 66.8% seizure reduction without cardiac complications positions Fintepla as a potentially transformative therapy for Dravet syndrome, though broader real‑world data will be essential to validate these trial findings.