The new experimental drug zorevunersen shows promise in treating children with Dravet syndrome, a severe genetic form of epilepsy caused by a mutation in the SCN1A gene.[1][2] In phase 1/2a clinical trials, treatment with multiple doses of 70 mg reduced the median seizure frequency by 73.6% 6 months after the last dose, and patients achieved a median of 7 (range 2–20) seizure-free days per 28 days.[2] In ongoing open-label extension studies with maintenance doses of 45 mg every 4 months, patients achieved seizure reductions of 53.0% to 87.0% from baseline by month 8.[2] The treatment improved patients' quality of life, cognition, behavior, and overall functioning.[1][2] Zorevunersen acts as an antisense oligonucleotide that increases the function of the NaV1.1 protein in nerve cells.[1][3] The FDA granted the drug Breakthrough Therapy Designation to Accelerate Development based on these data presented at the American Epilepsy Society 2024 meeting.[1] The results lead to the initiation of phase 3 studies to further verify efficacy and safety.[2][5]