Recent 8-K filings for SION

• September 14, 2026, 4:10 PM ET other material materiality 0.85 neutral item 2.05item 5.02item 8.01item 9.01 ◈ executive_change ×4

  Sionna cuts workforce 46%, plans Phase 2a trial for SION-451+SION-2222

  Board approved restructuring cutting ~46% of workforce, retaining core clinical capabilities for SION-451 and SION-2222.

• August 10, 2026, 7:15 AM ET other material materiality 0.85 negative item 8.01item 9.01

  Sionna's SION-719 Phase 2a misses sweat chloride endpoint; program halted as add-on

  SION-719 Phase 2a missed key endpoint: -1.0 mmol/L placebo-adjusted sweat chloride change (p=0.7); not advancing as add-on to SOC.

• August 6, 2026, 7:12 AM ET earnings materiality 0.55 neutral item 2.02item 9.01

  Sionna Therapeutics Q2 2026 net loss $29.9M; cash $268.3M; Phase 2a and Phase 1 trials on track for summer data

  Net loss of $29.9M for Q2 2026, compared to $18.1M in Q2 2025.

• June 18, 2026, 4:05 PM ET other materiality 0.10 neutral item 5.07 ◈ Shareholder Votes ×2

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

  Four Class II directors elected: H. Edward Fleming, Marcella Kuhlman Ruddy, Peter A. Thompson, Joanne Louise Viney.

• May 12, 2026, 7:08 AM ET earnings materiality 0.60 positive item 2.02item 9.01 ◈ Earnings Releases

  Sionna Therapeutics Q1 net loss $26.8M; Phase 2a enrollment completed for SION-719

  Net loss of $26.8M for Q1 2026, compared to $16.5M in Q1 2025.

• March 2, 2026, 6:59 PM ET earnings materiality 0.50 neutral item 2.02item 9.01

  Sionna Therapeutics Q4 2025 net loss $20.4M; cash $310.3M funds into 2028

  Net loss $20.4M (Q4) and $75.3M (FY 2025) vs $15.8M and $61.7M in 2024.

• November 5, 2025, 6:59 PM ET earnings materiality 0.70 positive item 2.02item 9.01

  Sionna Q3 net loss $20.3M; starts Phase 2a trial for SION-719; cash runway into 2028

  Net loss of $20.3M in Q3 2025 versus $25.4M in Q3 2024; R&D expenses fell to $16.0M from $24.6M due to prior year license charge.

• August 11, 2025, 7:59 PM ET earnings materiality 0.60 positive item 2.02item 9.01

  Sionna Therapeutics Q2 net loss $18.1M; positive Phase 1 data for NBD1 stabilizers

  Net loss $18.1M in Q2 2025 vs $8.6M in Q2 2024; R&D expenses $15.4M.

• June 13, 2025, 7:59 PM ET other materiality 0.15 neutral item 5.07

  Sionna Therapeutics annual meeting elects three Class I directors, ratifies auditor

  Shareholders elected Joshua Resnick, Bruce Booth, and Lucian Iancovici as Class I directors, each with over 42 million votes for.

• June 4, 2025, 7:59 PM ET other material materiality 0.70 positive item 7.01item 9.01

  Sionna reports positive Phase 1 data for NBD1 stabilizers SION-719 and SION-451; advances both to next trials

  Both SION-719 and SION-451 were generally well tolerated with no serious adverse events or discontinuations.

• May 12, 2025, 7:59 PM ET earnings materiality 0.65 neutral item 2.02item 9.01

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

  Net loss of $16.5M for Q1 2025, up from $11.8M in Q1 2024; R&D expenses $13.7M vs $10.2M.

• March 20, 2025, 7:59 PM ET earnings materiality 0.75 negative item 2.02item 9.01

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

  Net loss Q4 2024 $15.8M, full year $61.7M vs $47.3M in 2023; R&D spend $57.3M.

• February 10, 2025, 6:59 PM ET other materiality 0.15 neutral item 5.03item 9.01 ◈ Governance Changes ×2

  Sionna adopts amended charter/bylaws with IPO completion; eliminates written consent

  Amended charter authorizes 500M common shares and 10M undesignated preferred shares; prior preferred series removed.

Executive changes

Earnings & guidance

Materiality & sentiment trend

Max materiality 0.85 · Median 0.60 · Most common event earnings

4 positive 2 negative 7 neutral

source · SION on sec.gov