{"url_path":"/sec/upb/10-q/2026/item-5","section_key":"item-5","section_title":"Item 5 Other Information.","topic":"sec","document":{"doc_type":"10-Q","doc_date":"2026-05-13","source_url":"https://www.sec.gov/Archives/edgar/data/2022626/0001193125-26-220584-index.html","accession_number":"0001193125-26-220584","cik":"0002022626","ticker":"UPB","issuer_name":"Upstream Bio, Inc.","edgar_url":"https://www.sec.gov/Archives/edgar/data/2022626/0001193125-26-220584-index.html","primary_entity_key":"0002022626","primary_entity_name":"Upstream Bio, Inc."},"word_count":98,"has_tables":true,"body_markdown":"Item 5. Other Information.\n\n(a) None.\n\n(b) Not applicable.\n\n(c) From time to time, our officers (as defined in Rule 16a–1(f)) and directors may enter into Rule 10b5-1 or non-Rule 10b5-1 trading arrangements (as each such term is defined in Item 408 of Regulation S-K). During the quarter ended March 31, 2026, none of our directors or officers adopted, modified, or terminated a Rule 10b5-1 trading arrangement or other arrangement intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or any non-Rule 10b5-1 trading arrangement, as each term is defined in Item 408 of Regulation S-K.\n\n80"}