---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-058306"
form_type: "8-K"
ticker: "SION"
cik: "0002036042"
company_name: "Sionna Therapeutics, Inc."
filed_at: "2025-03-20T23:59:59+00:00"
generated_at: "2026-05-24T11:03:32.784599+00:00"
event_type: "earnings"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Sionna Therapeutics FY2024 net loss $61.7M; cash $168M plus $199.6M IPO net proceeds extend runway into 2028

## Summary
- Net loss Q4 2024 $15.8M, full year $61.7M vs $47.3M in 2023; R&D spend $57.3M.
- Cash, equivalents and marketable securities $168.0M as of Dec 2024; excluding $199.6M net IPO proceeds from February 2025.
- Upsized IPO raised $219M gross ($199.6M net) in Feb 2025; shares trading on Nasdaq under SION.
- Phase 1 MAD dosing completed for SION-451; final MAD cohort for SION-719 planned; topline data expected H1 2025.
- Plan to initiate Phase 2a POC trial in CF patients H2 2025 with topline data mid-2026; combination MAD trials also planned.

## SEC filing metadata
- accession: 0001193125-25-058306
- form_type: 8-K
- ticker: SION
- cik: 0002036042
- company_name: Sionna Therapeutics, Inc.
- filed_at: 2025-03-20T23:59:59+00:00
- event_type: earnings
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/2036042/000119312525058306/0001193125-25-058306-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/2036042/000119312525058306/d679677d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-058306
- JSON: https://secwatch.observer/filing/0001193125-25-058306.json
- Plain text: https://secwatch.observer/filing/0001193125-25-058306.txt

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