---
schema_version: "secwatch.filing_event.v1"
accession: "0002036042-25-000014"
form_type: "8-K"
ticker: "SION"
cik: "0002036042"
company_name: "Sionna Therapeutics, Inc."
filed_at: "2025-05-12T23:59:59+00:00"
generated_at: "2026-05-22T00:46:02.419102+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Sionna Therapeutics Q1 net loss $16.5M; cash $354.7M; Phase 1 dosing complete for two NBD1 stabilizers

## Summary
- Net loss of $16.5M for Q1 2025, up from $11.8M in Q1 2024; R&D expenses $13.7M vs $10.2M.
- Cash and cash equivalents $354.7M as of March 31, 2025, including $199.6M net IPO proceeds; runway into 2028.
- Phase 1 dosing completed for SION-719 and SION-451; topline data expected in Q2 2025.
- Phase 2a POC trial and at least one dual combination MAD trial on track for H2 2025; topline data mid-2026.

## SEC filing metadata
- accession: 0002036042-25-000014
- form_type: 8-K
- ticker: SION
- cik: 0002036042
- company_name: Sionna Therapeutics, Inc.
- filed_at: 2025-05-12T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/2036042/000203604225000014/0002036042-25-000014-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/2036042/000203604225000014/sion-20250512.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0002036042-25-000014
- JSON: https://secwatch.observer/filing/0002036042-25-000014.json
- Plain text: https://secwatch.observer/filing/0002036042-25-000014.txt

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