{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-26-018700","form_type":"8-K","ticker":"MBX","cik":"0001776111","company_name":"MBX Biosciences, Inc.","filed_at":"2026-01-22T23:59:59+00:00","discovered_at":"2026-05-14T18:02:36.138883+00:00","generated_at":"2026-05-16T08:50:27.328243+00:00","sec_items":["5.02","7.01","9.01"],"event_type":"leadership","sentiment":"neutral","materiality_score":0.4,"calibrated_materiality_score":0.4,"confidence":"high","headline":"MBX Biosciences appoints Laurie Stelzer as independent director and audit committee chair","bullets":["Laurie Stelzer appointed as Class I director effective Jan. 20, 2026, filling an existing board vacancy.","Stelzer will serve as chair of the Audit Committee, replacing Ed Mathers on that committee.","She brings CFO experience from Kailera, Orna, Mirati, Arena, Halozyme, and board roles at Sionna, PMV, Spyre.","Board size increased to eight directors; Stelzer is independent under Nasdaq standards."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-26-018700","json":"https://secwatch.observer/filing/0001193125-26-018700.json","markdown":"https://secwatch.observer/filing/0001193125-26-018700.md","text":"https://secwatch.observer/filing/0001193125-26-018700.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1776111/000119312526018700/0001193125-26-018700-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1776111/000119312526018700/mbx-20260120.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-16T08:50:27.328243+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":[],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}