Rapport Therapeutics, Inc. (NASDAQ: RAPP) has announced positive topline results from the phase 2a clinical trial of rap-219 (rap-219-fos-201) in patients with drug-resistant focal onset seizures. The trial demonstrated a statistically significant reduction in long episodes (LES) compared with baseline over the 8-week treatment period. The data also showed a statistically significant and clinically meaningful reduction in clinical seizures compared with baseline, with patients achieving a 77.8% reduction in clinical seizures and 24% achieving seizure freedom for the 8-week treatment period.
Key efficacy results from the trial include 85.2% of patients achieving ≥30% reduction in LES from baseline, 72.0% achieving ≥50% reduction in clinical seizures from baseline, and 24% achieving seizure freedom. The trial enrolled 30 patients with focal onset seizures who had an implanted RNS® system, and the primary efficacy endpoint was the change in frequency of RNS-recorded long episodes.
Rap-219 was generally well-tolerated in the trial, with no serious adverse events reported, and the majority of treatment-emergent adverse events being mild. The most common treatment-emergent adverse events reported were dizziness, headache, fatigue, fall, nausea, and somnolence.
The demographics and baseline characteristics of patients enrolled in the phase 2a study are consistent with those expected in future registrational trials. The trial enrolled 12 women and 18 men, with a mean age of 40.1 years. Patients were taking a median of 3 concomitant antiseizure medications, with the highest proportion of patients taking lamotrigine, levetiracetam, and cenobamate medications.
Rapport plans to host a conference call to discuss the data and provide a business update. The company also intends to initiate pivotal trials in the third quarter of 2026 and expects to present additional efficacy analyses and 8-week follow-up results in 2026.
Additionally, Rapport plans to initiate an open-label long-term safety trial for patients enrolled in the phase 2a trial to continue on rap-219, with preliminary results expected in the second half of 2026. The company is also continuing the development of a long-acting injectable (LAI) formulation of rap-219 and evaluating rap-219 in a phase 2 trial in bipolar mania, with topline results expected in the first half of 2027.
Rap-219 is a potential first-in-class, clinical-stage tarpg8-specific AMPA receptor (AMPAR) negative allosteric modulator (NAM). The compound is being evaluated as a potential treatment for drug-resistant focal onset seizures, bipolar disorder, and peripheral neuropathic pain.
Rapport Therapeutics is a clinical-stage biotechnology company dedicated to discovering and developing small molecule precision medicines for patients with neurological or psychiatric disorders. The company's precision neuroscience pipeline includes the lead investigational drug, rap-219, as well as additional preclinical and late-stage discovery stage programs targeting chronic pain and hearing disorders. The market has reacted to these announcements by moving the company's shares 126.95% to a price of $32.59. If you want to know more, read the company's complete 8-K report here.
