{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-25-065633","form_type":"8-K","ticker":"SPRO","cik":"0001701108","company_name":"Spero Therapeutics, Inc.","filed_at":"2025-03-27T23:59:59+00:00","discovered_at":"2026-05-14T18:03:04.491098+00:00","generated_at":"2026-05-24T03:57:46.535489+00:00","sec_items":["2.02","9.01"],"event_type":"earnings","sentiment":"negative","materiality_score":0.85,"calibrated_materiality_score":0.85,"confidence":"high","headline":"Spero posts Q4 net loss of $20.9M; revenue down 80% YoY; pipeline setbacks and SEC Wells Notice","bullets":["Net loss of $20.9M in Q4 2024 vs net income of $51.2M in Q4 2023; diluted EPS loss of $(0.38).","Total revenue fell to $15.0M from $73.5M YoY, driven by lower collaboration revenue from GSK and Pfizer.","Tebipenem HBr Phase 3 PIVOT-PO interim analysis expected Q2 2025; SPR720 Phase 2a missed primary endpoint with three cases of grade 3 hepatotoxicity; SPR206 discontinued.","Leadership change: Esther Rajavelu appointed Interim President and CEO in January 2025 following a Wells Notice from SEC related to disclosures in 2022.","Cash of $52.9M as of Dec 31, 2024; plus GSK milestones provide runway into Q2 2026."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-25-065633","json":"https://secwatch.observer/filing/0001193125-25-065633.json","markdown":"https://secwatch.observer/filing/0001193125-25-065633.md","text":"https://secwatch.observer/filing/0001193125-25-065633.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1701108/000119312525065633/0001193125-25-065633-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1701108/000119312525065633/d906623d8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-24T03:57:46.535489+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"}