{"filing":{"accession_number":"0001193125-26-265800","cik":"0002022626","ticker":"UPB","company_name":"Upstream Bio, Inc.","form":"8-K","filing_date":"2026-06-10","report_date":null,"primary_document":"upb-20260609.htm","primary_document_url":"https://www.sec.gov/Archives/edgar/data/2022626/000119312526265800/upb-20260609.htm"},"events":[{"id":5646,"run_id":4949,"accession_number":"0001193125-26-265800","anchor_item_number":"5.07","event_type":"shareholder_vote_results","event_domain":"governance","is_material":true,"confidence":0.98,"summary":"This is a classic Item 5.07 disclosure reporting the results of the 2026 Annual Meeting of Stockholders held on June 9, 2026. The filing presents voting results for two proposals: election of Class II directors (H. Edward Fleming, Jr., M.D. and Liam Ratcliffe, M.B.Ch.B., Ph.D., M.B.A.) and ratification of PricewaterhouseCoopers LLP as independent auditor. Both proposals passed with strong majorities, making this a routine but material shareholder governance event.","company_name":"Upstream Bio, Inc.","ticker":"UPB","filing_date":"2026-06-10","form":"8-K","submitted_at":null,"items":[{"id":5809,"accession_number":"0001193125-26-265800","item_number":"5.07","item_title":"Submission of Matters to a Vote of Security Holders.","event_type":"shareholder_vote_results","event_domain":"governance","is_material":true,"confidence":0.98,"reasoning":"This is a classic Item 5.07 disclosure reporting the results of the 2026 Annual Meeting of Stockholders held on June 9, 2026. The filing presents voting results for two proposals: election of Class II directors (H. Edward Fleming, Jr., M.D. and Liam Ratcliffe, M.B.Ch.B., Ph.D., M.B.A.) and ratification of PricewaterhouseCoopers LLP as independent auditor. Both proposals passed with strong majorities, making this a routine but material shareholder governance event.","classifier_version":"claude-haiku-4-5-20251001+prompt-9e0ffca5","taxonomy_version":"v1","classified_at":"2026-06-10T20:07:07.189759+00:00","company_name":"","ticker":null,"filing_date":""}]}],"classifications":[{"id":5809,"accession_number":"0001193125-26-265800","item_number":"5.07","item_title":"Submission of Matters to a Vote of Security Holders.","event_type":"shareholder_vote_results","event_domain":"governance","is_material":true,"confidence":0.98,"reasoning":"This is a classic Item 5.07 disclosure reporting the results of the 2026 Annual Meeting of Stockholders held on June 9, 2026. The filing presents voting results for two proposals: election of Class II directors (H. Edward Fleming, Jr., M.D. and Liam Ratcliffe, M.B.Ch.B., Ph.D., M.B.A.) and ratification of PricewaterhouseCoopers LLP as independent auditor. Both proposals passed with strong majorities, making this a routine but material shareholder governance event.","classifier_version":"claude-haiku-4-5-20251001+prompt-9e0ffca5","taxonomy_version":"v1","classified_at":"2026-06-10T20:07:07.189759+00:00","company_name":"Upstream Bio, Inc.","ticker":"UPB","filing_date":"2026-06-10"}]}