Sionna Therapeutics Inc (SION) News & EventsSIONSionna Therapeutics Inc

Sionna Therapeutics Presents Data at 2026 North American Cystic Fibrosis Conference

Sionna Therapeutics "announced data being presented at the 2026 North American Cystic Fibrosis Conference (NACFC) being held in Atlanta, Georgia on October 7-10, 2026. The oral presentation by Dr. Sawicki is a summary of the previously disclosed post hoc analyses of the PreciSION CF Phase 2a trial evaluating NBD1 stabilizer SION-719 when added to Trikafta. Although the trial did not achieve its key activity endpoint, post hoc analyses excluding three participants with PK patterns consistent with dosing non-adherence showed a mean placebo-adjusted sweat chloride reduction of 8.6 mmol/L."

Sionna Reduces Workforce by Approximately 46% to Cut Costs

Following the completion of a comprehensive review of its operations, Sionna's board of directors has approved a workforce reduction of approximately 46% and the company has implemented other cost-saving measures to focus its resources on advancing SION-451 + SION-2222 and extend its operating runway. Sionna expects to retain the core clinical, scientific, regulatory, technical, and corporate capabilities required to advance the dual combination program. The company currently estimates it will incur aggregate restructuring and related charges of approximately $6.4M. Sionna ended Q2 with approximately $268.3M in cash, cash equivalents, and marketable securities. The company estimates that the workforce reduction, discontinuation of investment in SION-719 as an add-on to standard of care, and other cost-saving measures will extend its cash runway into the second half of 2029.

Sionna Therapeutics Advances SION-451 + SION-2222 into Phase 2a Trial

Sionna Therapeutics announced plans to advance SION-451 + SION-2222, its preferred proprietary dual combination, into the AscenSION CF Phase 2a proof-of-concept, or POC, trial, and results from the company's post hoc analysis of the PreciSION CF Phase 2a trial. The decision to advance SION-451 + SION-2222 follows an extensive review of clinical, pharmacokinetic and nonclinical data from PreciSION CF. Learnings from that trial and the previous Phase 1 dual combination trial will inform the development strategy for the dual combination. The Company continues to believe that directly stabilizing NBD1 in combination with a complementary CFTR modulator has the potential to meaningfully improve CFTR function. The AscenSION CF POC will be an open-label trial evaluating adults with CF homozygous for F508del treated with SION-451 + SION-2222 for 28 days. Participants will switch from Trikafta to SION-451 + SION-2222, and the trial will assess sweat chloride, safety, and PK. The design will incorporate key learnings from PreciSION CF with respect to dosing adherence and sweat chloride variability, and the trial is expected to initiate in the first quarter of 2027. The decision to advance SION-451 + SION-2222 is supported by results from the Phase 1 healthy volunteer trial of SION-451-based dual combinations, for which the Company announced topline results on August 10, 2026. The trial achieved its safety, tolerability, and PK objectives. SION-451 + SION-2222 was identified as the preferred dual combination based on target exposure coverage, and the go-forward SION-451 twice daily + SION-2222 once daily regimen demonstrated a favorable tolerability profile. Phase 1 exposures of the planned doses were within the range associated with meaningful improvement in CFTR function in Sionna's CFHBE assay.