---
schema_version: "secwatch.filing_event.v1"
accession: "0001628280-26-044263"
form_type: "8-K"
ticker: "SION"
cik: "0002036042"
company_name: "Sionna Therapeutics, Inc."
filed_at: "2026-06-18T20:05:31+00:00"
generated_at: "2026-06-18T20:12:19.347229+00:00"
event_type: "other"
sentiment: "neutral"
materiality_score: 0.1
calibrated_materiality_score: 0.1
confidence: "high"
source: SEC EDGAR
---

# Sionna Therapeutics annual meeting results: all director nominees elected, auditor ratified

## Summary
- Four Class II directors elected: H. Edward Fleming, Marcella Kuhlman Ruddy, Peter A. Thompson, Joanne Louise Viney.
- Ratification of Deloitte & Touche LLP as independent auditor for FY 2026 approved with 43,291,215 votes for.
- Meeting held June 17, 2026; 45,142,330 shares outstanding as of record date April 21, 2026.

## SEC filing metadata
- accession: 0001628280-26-044263
- form_type: 8-K
- ticker: SION
- cik: 0002036042
- company_name: Sionna Therapeutics, Inc.
- filed_at: 2026-06-18T20:05:31+00:00
- event_type: other
- sentiment: neutral
- materiality_score: 0.1
- calibrated_materiality_score: 0.1
- confidence: high
- sec_items: 5.07
- EDGAR index: https://www.sec.gov/Archives/edgar/data/2036042/000162828026044263/0001628280-26-044263-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/2036042/000162828026044263/sion-20260617.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001628280-26-044263
- JSON: https://secwatch.observer/filing/0001628280-26-044263.json
- Plain text: https://secwatch.observer/filing/0001628280-26-044263.txt

## Key facts
- Shareholder Votes
  Sionna Therapeutics, Inc. shareholders approved Election of four Class II directors at the 2026-06-17 meeting.
  - Proposal: director election
  - Outcome: passed
  - Meeting: 2026-06-17
  source text: 1. To elect four nominees as Class II directors: H. Edward Fleming, Jr., M.D., Marcella Kuhlman Ruddy, M.D., Peter A. Thompson, M.D., and Joanne Louise Viney, Ph.D., each to hold office until the Company's Annual Meeting of Stockholders in 2029.
  evidence_url: https://www.sec.gov/Archives/edgar/data/2036042/000162828026044263/0001628280-26-044263-index.htm
- Shareholder Votes
  Sionna Therapeutics, Inc. shareholders approved Ratification of appointment of Deloitte & Touche LLP as independent registered public accounting firm for fiscal year ending December 31, 2026 at the 2026-06-17 meeting.
  - Proposal: auditor ratification
  - Outcome: passed
  - Meeting: 2026-06-17
  source text: 2. To ratify the appointment of Deloitte & Touche LLP as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2026.
  evidence_url: https://www.sec.gov/Archives/edgar/data/2036042/000162828026044263/0001628280-26-044263-index.htm

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