{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-26-390577","form_type":"8-K","ticker":"SION","cik":"0002036042","company_name":"Sionna Therapeutics, Inc.","filed_at":"2026-09-14T20:10:18+00:00","discovered_at":"2026-09-14T20:11:02.865805+00:00","generated_at":"2026-09-14T20:11:54.333604+00:00","sec_items":["2.05","5.02","8.01","9.01"],"event_type":"other_material","sentiment":"neutral","materiality_score":0.85,"calibrated_materiality_score":0.85,"confidence":"high","headline":"Sionna cuts workforce 46%, plans Phase 2a trial for SION-451+SION-2222","bullets":["Board approved restructuring cutting ~46% of workforce, retaining core clinical capabilities for SION-451 and SION-2222.","Estimated restructuring charges of ~$6.4M, including $5.3M severance and $0.7M contract close-out for SION-719.","Chief Business Officer Caroline Stark Beer terminated without cause effective Sept 15, 2026; severance benefits approved.","Stock options repriced to closing price on Sept 17, 2026 for retained employees; original price reinstated if exercised before 18 months.","Plans to advance SION-451+SION-2222 into Phase 2a proof-of-concept trial initiating Q1 2027; cash runway extended into H2 2029."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-26-390577","json":"https://secwatch.observer/filing/0001193125-26-390577.json","markdown":"https://secwatch.observer/filing/0001193125-26-390577.md","text":"https://secwatch.observer/filing/0001193125-26-390577.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/2036042/000119312526390577/0001193125-26-390577-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/2036042/000119312526390577/d148638d8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-09-14T20:11:54.333604+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[{"claim_id":"385a008cca","claim":"Jennifer Fitzpatrick changed role as Head of Program Management at Sionna Therapeutics, Inc..","evidence_excerpt":"Jennifer Fitzpatrick, the Company’s Chief Legal Officer, assumed the additional role of Head of Program Management","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/2036042/000119312526390577/0001193125-26-390577-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"assumed"},{"label":"Role","value":"Head of Program Management"}],"fact_type":"executive_change"},{"claim_id":"3a925eb265","claim":"Elena Ridloff changed role as Chief Business Officer at Sionna Therapeutics, Inc..","evidence_excerpt":"Elena Ridloff, the Company’s Chief Financial Officer, assumed the additional role of Chief Business Officer","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/2036042/000119312526390577/0001193125-26-390577-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"assumed"},{"label":"Role","value":"Chief Business Officer"}],"fact_type":"executive_change"},{"claim_id":"a70e484702","claim":"Caroline Stark Beer was terminated as Chief Business Officer at Sionna Therapeutics, Inc..","evidence_excerpt":"the employment of Caroline Stark Beer, M.B.A., the Company’s Chief Business Officer, was terminated without cause, effective as of September 15, 2026","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/2036042/000119312526390577/0001193125-26-390577-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"terminated"},{"label":"Role","value":"Chief Business Officer"}],"fact_type":"executive_change"},{"claim_id":"e7a86c4cb8","claim":"Charlotte McKee changed role as Head of Research and Development at Sionna Therapeutics, Inc..","evidence_excerpt":"Charlotte McKee, the Company’s Chief Medical Officer, assumed the additional role of Head of Research and Development","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/2036042/000119312526390577/0001193125-26-390577-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"assumed"},{"label":"Role","value":"Head of Research and Development"}],"fact_type":"executive_change"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}