{"filing":{"accession_number":"0001728117-26-000064","cik":"0001728117","ticker":"GOSS","company_name":"Gossamer Bio, Inc.","form":"8-K","filing_date":"2026-07-27","report_date":"2026-07-23","primary_document":"goss-20260723.htm","primary_document_url":"https://www.sec.gov/Archives/edgar/data/1728117/000172811726000064/goss-20260723.htm"},"events":[{"id":20639,"run_id":18578,"accession_number":"0001728117-26-000064","anchor_item_number":"1.01","event_type":"ma_activity","event_domain":"operational","is_material":true,"confidence":0.92,"summary":"Gossamer reacquired worldwide development and commercial rights to seralutinib from Chiesi through termination of their Collaboration and License Agreement dated May 3, 2024. The transaction consolidates global operational control, returns the U.S. 50/50 profit share and ex-U.S. rights to Gossamer, and includes a $5 million payment from Chiesi plus future milestone and royalty obligations.","company_name":"Gossamer Bio, Inc.","ticker":"GOSS","filing_date":"2026-07-27","form":"8-K","submitted_at":null,"items":[{"id":20056,"accession_number":"0001728117-26-000064","item_number":"1.01","item_title":"Entry Into a Material Definitive Agreement.","event_type":"ma_activity","event_domain":"operational","is_material":true,"confidence":0.92,"reasoning":"Gossamer reacquired worldwide development and commercial rights to seralutinib from Chiesi through termination of their Collaboration and License Agreement dated May 3, 2024. This represents a material change in control and ownership of development/commercialization rights—Gossamer regained the U.S. 50/50 profit share and ex-U.S. rights, consolidating global operational control ahead of a planned NDA submission. The transaction includes a $5 million payment from Chiesi to Gossamer, capped royalties, and milestone payments, fundamentally restructuring the parties' economic and operational relationship to the seralutinib program.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"","ticker":null,"filing_date":""},{"id":20057,"accession_number":"0001728117-26-000064","item_number":"1.02","item_title":"Termination of a Material Definitive Agreement.","event_type":"ma_activity","event_domain":"operational","is_material":true,"confidence":0.92,"reasoning":"Gossamer reacquired worldwide development and commercial rights to seralutinib from Chiesi through termination of their Collaboration and License Agreement. This transaction consolidates global control of the program, eliminates the prior 50/50 U.S. profit share, returns ex-U.S. rights to Gossamer, and involves a $5 million payment from Chiesi plus future milestone and royalty obligations. The reacquisition materially affects the company's strategic position, economics, and operational control ahead of a planned NDA submission, making it a material acquisition of rights under Item 1.02.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"","ticker":null,"filing_date":""},{"id":20058,"accession_number":"0001728117-26-000064","item_number":"2.02","item_title":"Results of Operations and Financial Condition.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"The Item 2.02 disclosure centers on a preliminary cash position ($57.0 million as of June 30, 2026) subject to completion of financial closing procedures. While Item 2.02 typically covers earnings releases, this filing contains no complete quarterly financial results—only an unaudited cash estimate. The supplemental press release (EX-99.1) reveals the material events are regulatory progress (FDA Pre-NDA meeting and planned NDA submission), reacquisition of worldwide rights to seralutinib from Chiesi, and shareholder approval of a convertible note exchange and reverse stock split. The cash disclosure alone is insufficient to constitute an earnings release, and the Item 2.02 language explicitly disclaims filing status. The core material disclosures are operational (regulatory pathway, rights reacquisition) and governance (shareholder votes, capital structure changes), making operational_other the most appropriate classification for this Item 2.02 section.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"","ticker":null,"filing_date":""},{"id":20059,"accession_number":"0001728117-26-000064","item_number":"7.01","item_title":"Regulation FD Disclosure.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.72,"reasoning":"The disclosure centers on multiple material operational and strategic developments: (1) FDA regulatory progress toward a planned September 2026 NDA submission for seralutinib in PAH following a Pre-NDA Type B meeting; (2) reacquisition of worldwide development and commercial rights to seralutinib from Chiesi, consolidating global control and returning ex-U.S. rights and the 50/50 U.S. profit share to Gossamer; and (3) shareholder approval of a convertible note exchange and reverse stock split authorization. While the filing also references capital structure improvements (debt reduction of ~$115.9 million), the primary focus is the strategic reacquisition of rights and regulatory pathway clarity, which are operational/strategic milestones rather than a discrete financial event type (e.g., debt issuance or M\u0026A completion). The reacquisition involves termination of an existing license agreement and receipt of a $5 million payment, but is framed as a rights consolidation ahead of a regulatory milestone rather than a traditional acquisition or disposition.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"","ticker":null,"filing_date":""},{"id":20060,"accession_number":"0001728117-26-000064","item_number":"8.01","item_title":"Other Events.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"The disclosure centers on a regulatory milestone—FDA feedback from a Pre-NDA Type B meeting characterizing statistical significance and treatment effect as \"review issues rather than filing issues,\" enabling a planned NDA submission in September 2026 for seralutinib in PAH. While this is a material operational/regulatory development affecting the company's drug development pathway and timeline, it does not fit neatly into the specific event categories (e.g., it is not a completed M\u0026A, a restatement, or a going-concern issue). The reacquisition of worldwide rights from Chiesi is also disclosed but is secondary to the regulatory update. This is best classified as an operational milestone with regulatory significance rather than a distinct financial or governance event.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"","ticker":null,"filing_date":""}]}],"classifications":[{"id":20056,"accession_number":"0001728117-26-000064","item_number":"1.01","item_title":"Entry Into a Material Definitive Agreement.","event_type":"ma_activity","event_domain":"operational","is_material":true,"confidence":0.92,"reasoning":"Gossamer reacquired worldwide development and commercial rights to seralutinib from Chiesi through termination of their Collaboration and License Agreement dated May 3, 2024. This represents a material change in control and ownership of development/commercialization rights—Gossamer regained the U.S. 50/50 profit share and ex-U.S. rights, consolidating global operational control ahead of a planned NDA submission. The transaction includes a $5 million payment from Chiesi to Gossamer, capped royalties, and milestone payments, fundamentally restructuring the parties' economic and operational relationship to the seralutinib program.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"Gossamer Bio, Inc.","ticker":"GOSS","filing_date":"2026-07-27"},{"id":20057,"accession_number":"0001728117-26-000064","item_number":"1.02","item_title":"Termination of a Material Definitive Agreement.","event_type":"ma_activity","event_domain":"operational","is_material":true,"confidence":0.92,"reasoning":"Gossamer reacquired worldwide development and commercial rights to seralutinib from Chiesi through termination of their Collaboration and License Agreement. This transaction consolidates global control of the program, eliminates the prior 50/50 U.S. profit share, returns ex-U.S. rights to Gossamer, and involves a $5 million payment from Chiesi plus future milestone and royalty obligations. The reacquisition materially affects the company's strategic position, economics, and operational control ahead of a planned NDA submission, making it a material acquisition of rights under Item 1.02.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"Gossamer Bio, Inc.","ticker":"GOSS","filing_date":"2026-07-27"},{"id":20058,"accession_number":"0001728117-26-000064","item_number":"2.02","item_title":"Results of Operations and Financial Condition.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"The Item 2.02 disclosure centers on a preliminary cash position ($57.0 million as of June 30, 2026) subject to completion of financial closing procedures. While Item 2.02 typically covers earnings releases, this filing contains no complete quarterly financial results—only an unaudited cash estimate. The supplemental press release (EX-99.1) reveals the material events are regulatory progress (FDA Pre-NDA meeting and planned NDA submission), reacquisition of worldwide rights to seralutinib from Chiesi, and shareholder approval of a convertible note exchange and reverse stock split. The cash disclosure alone is insufficient to constitute an earnings release, and the Item 2.02 language explicitly disclaims filing status. The core material disclosures are operational (regulatory pathway, rights reacquisition) and governance (shareholder votes, capital structure changes), making operational_other the most appropriate classification for this Item 2.02 section.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"Gossamer Bio, Inc.","ticker":"GOSS","filing_date":"2026-07-27"},{"id":20059,"accession_number":"0001728117-26-000064","item_number":"7.01","item_title":"Regulation FD Disclosure.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.72,"reasoning":"The disclosure centers on multiple material operational and strategic developments: (1) FDA regulatory progress toward a planned September 2026 NDA submission for seralutinib in PAH following a Pre-NDA Type B meeting; (2) reacquisition of worldwide development and commercial rights to seralutinib from Chiesi, consolidating global control and returning ex-U.S. rights and the 50/50 U.S. profit share to Gossamer; and (3) shareholder approval of a convertible note exchange and reverse stock split authorization. While the filing also references capital structure improvements (debt reduction of ~$115.9 million), the primary focus is the strategic reacquisition of rights and regulatory pathway clarity, which are operational/strategic milestones rather than a discrete financial event type (e.g., debt issuance or M\u0026A completion). The reacquisition involves termination of an existing license agreement and receipt of a $5 million payment, but is framed as a rights consolidation ahead of a regulatory milestone rather than a traditional acquisition or disposition.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"Gossamer Bio, Inc.","ticker":"GOSS","filing_date":"2026-07-27"},{"id":20060,"accession_number":"0001728117-26-000064","item_number":"8.01","item_title":"Other Events.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"The disclosure centers on a regulatory milestone—FDA feedback from a Pre-NDA Type B meeting characterizing statistical significance and treatment effect as \"review issues rather than filing issues,\" enabling a planned NDA submission in September 2026 for seralutinib in PAH. While this is a material operational/regulatory development affecting the company's drug development pathway and timeline, it does not fit neatly into the specific event categories (e.g., it is not a completed M\u0026A, a restatement, or a going-concern issue). The reacquisition of worldwide rights from Chiesi is also disclosed but is secondary to the regulatory update. This is best classified as an operational milestone with regulatory significance rather than a distinct financial or governance event.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-07-27T20:02:58.602655+00:00","company_name":"Gossamer Bio, Inc.","ticker":"GOSS","filing_date":"2026-07-27"}]}