Catalyst Calendar

Mon, Sep 14, 2026

1 updates

4:01 PM

Sionna Therapeutics Announces Plans to Advance SION-451 + SION-2222 Dual Combination into Phase 2a Proof-of-Concept Trial

Post hoc analyses of SION-719 PreciSION CF subset showed a mean placebo-adjusted sweat chloride reduction of up to -8.6 mmol/L consistent with NBD1 biological activity Dual combination Phase 2a trial expected to initiate in first quarter of 2027 46% workforce reduction and other cost-saving

Trial Results • Phase 2Results event Mon, Aug 10, 2026sionnatx.com

Mon, Aug 10, 2026

1 updates

SION

7:00 AM

Sionna Therapeutics Reports Topline Data from Two Development Programs in Cystic Fibrosis and Provides Corporate Update

SION-719 Phase 2a proof-of-concept trial did not achieve key activity endpoint of sweat chloride reduction when added to standard of care; Company is not advancing SION-719 as an add-on to standard of care Potential confounders in SION-719 Phase 2a trial are being evaluated to inform next steps for

Trial Results • Phase 2Results call Mon, Aug 10, 2026, 8:00 AM ETsionnatx.com

Thu, Aug 6, 2026

1 updates

SION

7:00 AM

Sionna Therapeutics Reports Second Quarter 2026 Financial Results

PreciSION CF Phase 2a proof-of-concept trial evaluating NBD1 stabilizer SION-719 as an add-on to standard of care is on track for topline data summer of 2026 Phase 1 trial evaluating NBD1 stabilizer SION-451 in proprietary dual combinations with SION-2222 and with SION-109 also is on track for

sionnatx.com