{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-26-369674","form_type":"8-K","ticker":"MBX","cik":"0001776111","company_name":"MBX Biosciences, Inc.","filed_at":"2026-08-27T12:34:34+00:00","discovered_at":"2026-08-27T12:35:00.391344+00:00","generated_at":"2026-08-27T12:35:03.745150+00:00","sec_items":["7.01","8.01","9.01"],"event_type":"other_material","sentiment":"positive","materiality_score":0.7,"calibrated_materiality_score":0.7,"confidence":"high","headline":"MBX Biosciences doses first patient in Phase 3 oPTimize trial of canvuparatide for hypoparathyroidism","bullets":["First patient dosed in pivotal Phase 3 oPTimize trial (NCT07699471) of once-weekly canvuparatide in chronic hypoparathyroidism.","Trial enrolls ~160 adults, randomized 3:1 canvuparatide vs placebo over 26-week double-blind period, then 78-week open-label extension.","Primary endpoint: composite responder at Week 26 (normal serum calcium, no active vitamin D, calcium ≤600 mg/day, no dose increase).","Builds on positive Phase 2 Avail results showing normalized serum calcium, reduced urinary calcium, restored bone metabolism, increased eGFR.","Canvuparatide administered once weekly using commercial-intent device; CEO cites potential as new standard of care."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-26-369674","json":"https://secwatch.observer/filing/0001193125-26-369674.json","markdown":"https://secwatch.observer/filing/0001193125-26-369674.md","text":"https://secwatch.observer/filing/0001193125-26-369674.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1776111/000119312526369674/0001193125-26-369674-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1776111/000119312526369674/mbx-20260827.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-08-27T12:35:03.745150+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"}