Shares of Rapport Therapeutics (NASDAQ:RAPP) skyrocketed 160% after the biotech firm released encouraging topline data from a Phase 2a study of its experimental therapy RAP-219 in patients with focal onset seizures.
The trial achieved its primary endpoint with strong statistical significance, showing a 71% median reduction in long seizure episodes, a recognized electrographic marker of seizure activity. Clinical outcomes were also notable: patients experienced a 77.8% median reduction in clinical seizures compared with baseline, and nearly one-quarter (24%) of participants remained seizure-free throughout the eight-week treatment window.
RAP-219, designed as a first-in-class TARPγ8-specific AMPAR negative allosteric modulator, demonstrated a favorable safety profile. Most adverse events were mild (78.5%) or moderate (21.5%), with no serious cases reported. The most frequently observed side effects included dizziness, headache, and fatigue.
“The efficacy data and tolerability profile seen in the Phase 2a trial demonstrate RAP-219’s potential to be an important treatment for patients with drug-resistant focal onset seizures,” said Abe Ceesay, chief executive officer of Rapport.
Following these results, the company intends to initiate two Phase 3 pivotal trials in the third quarter of 2026, after holding an end-of-Phase 2 meeting with the FDA in late 2025. Rapport is also developing a long-acting injectable version of RAP-219 to improve treatment adherence, and is testing the therapy in a separate Phase 2 trial for bipolar mania, with readouts expected in the first half of 2027.
Rapport Therapeutics stock price
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