---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-167078"
form_type: "8-K"
ticker: "RAPP"
cik: "0002012593"
company_name: "Rapport Therapeutics, Inc."
filed_at: "2026-04-21T23:59:59+00:00"
generated_at: "2026-05-15T05:11:04.281418+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# RAP-219 Phase 2a follow-up shows sustained seizure reduction; half-life updated to ~22 days

## Summary
- 90% median reduction in clinical seizures in weeks 9-12; 59% in weeks 13-16, demonstrating sustained effect after treatment cessation.
- Updated half-life of ~22 days (prior 14 days) with plasma concentrations maintaining >75% receptor occupancy through week 12.
- Two Phase 3 FOS trials (FOCUS 1 & 2) expected to start Q2 2026; open-label extension ongoing with initial data H2 2026.
- RAP-219 well tolerated; 2 mild treatment-related AEs, 3 SAEs unrelated to drug. Phase 2 bipolar mania topline expected H1 2027.

## SEC filing metadata
- accession: 0001193125-26-167078
- form_type: 8-K
- ticker: RAPP
- cik: 0002012593
- company_name: Rapport Therapeutics, Inc.
- filed_at: 2026-04-21T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/2012593/000119312526167078/0001193125-26-167078-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/2012593/000119312526167078/rapp-20260421.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-167078
- JSON: https://secwatch.observer/filing/0001193125-26-167078.json
- Plain text: https://secwatch.observer/filing/0001193125-26-167078.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.