Biogen, Stoke Boost Epilepsy Drug’s Blockbuster Potential With Early Seizure Reduction Data on December 08, 2025 American Epilepsy Society 2025 Antisense Oligonucleotides Biogen blockbuster drug EMPEROR Phase III trial Epilepsy Infantile Severe Myoclonic Epilepsy Seizures Stoke Therapeutics Zorevunersen +