Independent
Tenure on this board
1.4 yrs
Also a director at
Crispr Therapeutics AG (CRSP)Upstream Bio Inc (UPB)
Meeting calendar
SION · Annual meeting · Wednesday, June 17, 2026
Sionna Therapeutics Inc
4 nominees · 2 ballot items.
Stockholders will vote to elect four Class II directors (H. Edward Fleming, Jr.; Marcella Kuhlman Ruddy; Peter A. Thompson; Joanne Louise Viney) for three-year terms and to ratify Deloitte & Touche LLP as the company’s independent registered public accounting firm for the fiscal year ending December 31, 2026.
Market cap
$2.2B
1Y TSR
+120.2%
Board grade
C-
Record date
Apr 21, 2026
Filing
DEF 14A
Meeting concluded · Jun 17, 2026
Follow how the vote landed and what changed on Sionna Therapeutics Inc’s board — director track records, governance grades, and ongoing monitoring — on the Boardroom Alpha platform.
Proposals
On the ballot2
- 1
Election of Class II Directors
ManagementBoard: FORElect four 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. — to serve three-year terms expiring at the 2029 annual meeting.
- 2
Ratification of the Appointment of Deloitte & Touche LLP as Independent Registered Public Accounting Firm
ManagementBoard: FORRatify the appointment of Deloitte & Touche LLP as Sionna’s independent registered public accounting firm for the fiscal year ending December 31, 2026.
Director elections
Nominees on the ballot4
Independent
Tenure on this board
1.4 yrs
Also a director at
Upstream Bio Inc (UPB)
Independent
Tenure on this board
1.4 yrs
Also a director at
Corvus Pharmaceuticals Inc (CRVS)Edgewise Therapeutics Inc (EWTX)Ars Pharmaceuticals Inc (SPRY)
Independent
Tenure on this board
1.4 yrs
Also a director at
Lenz Therapeutics Inc (LENZ)
Ownership
Latest 13F quarterTop institutional holders10
| # | Owner | % of shares | Shares | Value |
|---|---|---|---|---|
| 1 | RA CAPITAL MANAGEMENT, L.P. | 21.9% | 9,905,045 | $397M |
| 2 | TPG GP A, LLC | 14.4% | 6,494,962 | $260M |
| 3 | ORBIMED ADVISORS LLCActivist | 7.8% | 3,530,702 | $142M |
| 4 | VIKING GLOBAL INVESTORS LP | 7.1% | 3,195,181 | $128M |
| 5 | Atlas Venture Life Science Advisors, LLC | 6.6% | 2,995,602 | $120M |
| 6 | Enavate Sciences GP, LLC | 5.5% | 2,478,030 | $99M |
| 7 | JENNISON ASSOCIATES LLC | 3.2% | 1,451,220 | $58M |
| 8 | CITADEL ADVISORS LLC | 2.5% | 1,139,874 | $46M |
| 9 | VANGUARD CAPITAL MANAGEMENT LLC | 2.3% | 1,029,497 | $41M |
| 10 | DEERFIELD MANAGEMENT COMPANY, L.P. | 2.1% | 970,590 | $39M |
Peers
Nearest market capOther Healthcare sector meetings6
Upcoming shareholder meetings at Sionna Therapeutics Inc’s closest sector peers — compare boards, ballots, and ownership across the cohort.
Prestige Consumer Healthcare IncPBH
Annual meeting·Aug 4, 2026·$2.4B
Trulieve Cannabis CorpTRLV
Special meeting·Aug 5, 2026·$1.7B
Anaptysbio IncANAB
Annual meeting·Aug 11, 2026·$1.7B
Avanos Medical IncAVNS
Special meeting·Jul 22, 2026·$1.2B
Haemonetics CorpHAE
Annual meeting·Jul 24, 2026·$3.5B
Organon & CoOGN
Special meeting·Jul 23, 2026·$3.6B
Reference
Frequently asked questions
- When is the Sionna Therapeutics Inc 2026 annual meeting?
- Sionna Therapeutics Inc (SION) holds its 2026 annual shareholder meeting on Wednesday, June 17, 2026.
- What is the record date for the Sionna Therapeutics Inc 2026 meeting?
- The record date for the Sionna Therapeutics Inc 2026 meeting is Tuesday, April 21, 2026. Shareholders of record on or before that date are eligible to vote.
- Who are the director nominees for Sionna Therapeutics Inc's 2026 meeting?
- The board is presenting 4 director nominees at the Sionna Therapeutics Inc 2026 meeting, listed with their independence status and background.
- What proposals will shareholders vote on at the Sionna Therapeutics Inc 2026 meeting?
- Shareholders will vote on 2 proposals at the Sionna Therapeutics Inc 2026 meeting, each tagged with who proposed it and the board's recommendation.
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