{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-24-000249","form_type":"8-K","ticker":"SPRO","cik":"0001701108","company_name":"Spero Therapeutics, Inc.","filed_at":"2024-01-02T23:59:59+00:00","discovered_at":"2026-05-14T18:03:25.163342+00:00","generated_at":"2026-06-07T05:20:46.818944+00:00","sec_items":["7.01","8.01","9.01"],"event_type":"other_material","sentiment":"positive","materiality_score":0.75,"calibrated_materiality_score":0.75,"confidence":"high","headline":"Spero starts Phase 3 PIVOT-PO trial of tebipenem HBr; $95M milestone payable over two years from GSK","bullets":["First patient first visit for Phase 3 PIVOT-PO trial (cUTI/AP) targeting ~2,648 patients.","Primary endpoint: overall response (composite of clinical cure + microbiological eradication) at test-of-cure.","Non-inferiority vs IV imipenem cilastatin with 10% NI margin in microbiological ITT population.","GSK license: $95M development milestone payable in 4 equal semiannual installments over 2 years.","Additional milestones: $25M on FDA submission, up to $150M commercial, up to $225M sales, plus tiered royalties."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-24-000249","json":"https://secwatch.observer/filing/0001193125-24-000249.json","markdown":"https://secwatch.observer/filing/0001193125-24-000249.md","text":"https://secwatch.observer/filing/0001193125-24-000249.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1701108/000119312524000249/0001193125-24-000249-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1701108/000119312524000249/d360654d8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-07T05:20:46.818944+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"}