UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 __________________________________________________________________________________ FORM 10-K __________________________________________________________________________________ ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission file number: 001-38796 _____ ...

Seralutinib (GB002) for Pulmonary Arterial Hypertension (PAH) - Seralutinib (GB002) is an inhaled PDGFR, CSF1R, and c-KIT inhibitor being developed for PAH, with Phase 2 enrollment completed and topline results expected in the second half of November/first half of December 2022 [4, 6] - The Phase 3 IMPRES study of Imatinib in PAH showed a 32-meter improvement in 6-Minute Walk Distance (6MWD) and a 32% reduction in Pulmonary Vascular Resistance (PVR), but had a high rate of GI side effects (44% SAE rate) and discontinuations (33% for the imatinib group) [12] - Seralutinib is designed for inhalation with limited oral bioavailability (~5%) to mitigate systemic adverse events associated with Imatinib [14] - Preclinical data shows Seralutinib treatment led to a significant improvement in Right Ventricular Systolic Pressure (RVSP) and reduced circulating levels of NT-proBNP in a SuHx PAH study [23] - Phase 1b study in PAH patients showed that all 8 subjects completed the 14-day treatment period, and 2 subjects entered and completed the Open-Label Extension (OLE) receiving 90 mg BID [30] GB5121 & GB7208 for CNS Lymphoma (PCNSL) and Multiple Sclerosis (MS) - GB5121 is a CNS-penetrant BTK inhibitor in Phase 1b/2 development for relapsed/refractory primary CNS lymphoma (PCNSL), while GB7208 is in preclinical development for Multiple Sclerosis (MS) [4, 46] - Preclinical mouse models suggest Gossamer BTK inhibitors have best-in-class CNS penetration [49] - GB5121 and GB7208 are highly selective BTK inhibitors based on kinome scans [52] - In the US, approximately 1,500 new PCNSL patients are diagnosed each year, with a median overall survival (OS) of 26 months [57] Financial Overview - As of June 30, 2022, Gossamer Bio had approximately $342 million in cash, cash equivalents, and marketable securities (pro forma for July 2022 PIPE), $30 million in debt, and $200 million in principal of convertible notes outstanding [73]

Corporate Presentation April 2022 Forward Looking Statement 2 This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation, including statements regarding our future results of operations and financial position, business strategy, prospective products, product approvals, research and development costs, timing and likelihood of success, plans and objectives of management for future operations, and future results of current and ...

Financial Data and Key Metrics Changes - The company ended Q3 2021 with $366 million in cash and cash equivalents, which is expected to fund operations well into the second half of 2023 [18] - Research and development expenses for Q3 2021 were approximately $43.2 million, compared to $41.8 million in Q3 2020, indicating a slight increase [18] - General and administrative expenses were $12.5 million in Q3 2021, up from $11.4 million in the same period in 2020 [18] - The net loss for Q3 2021 was $60.2 million, equating to $0.80 per share, consistent with the net loss of $57.8 million and $0.80 per share reported in Q3 2020 [18] Business Line Data and Key Metrics Changes - The company is focused on its inhaled kinase inhibitor, seralutinib, for pulmonary arterial hypertension, with a revised guidance for top-line data readout from the TORREY Phase II study now expected in the second half of 2022 [6][8] - Enrollment for the SHIFT-UC Phase II study in ulcerative colitis patients has been completed, showcasing the drug's appeal during the pandemic [11] - The company has introduced new clinical stage product candidates, GB5121 and GB7208, targeting CNS conditions, with GB5121 already in Phase I trials [14][15] Market Data and Key Metrics Changes - The company has faced challenges in clinical trial enrollment due to the COVID-19 pandemic, particularly with the delta variant impacting staffing at clinical sites [8][9] - Increased engagement with clinical sites is being observed as the delta variant's impact diminishes, allowing for improved enrollment rates [10] Company Strategy and Development Direction - The company is positioning GB004 as a favorable option for patients with mild-to-moderate ulcerative colitis, particularly as safety concerns arise with existing treatments [11][36] - The strategic focus includes leveraging the unique properties of GB5121 and GB7208 to address neuroinflammatory and neurodegenerative conditions, with plans for further trials in 2022 [14][15] Management's Comments on Operating Environment and Future Outlook - Management acknowledges the ongoing uncertainties related to COVID-19 but remains optimistic about enrollment rates and the potential for timely data release [28][30] - The company is committed to navigating the challenges posed by the pandemic while maintaining focus on its clinical development timelines [10][30] Other Important Information - The company has designed its clinical trials with flexibility to adapt to COVID-related challenges without compromising study integrity [32] - The SHIFT-UC study is powered to achieve secondary endpoints related to clinical response and mucosal healing, indicating a robust trial design [25] Q&A Session Summary Question: Update on TORREY study patient enrollment and additional sites - Management did not disclose specific patient numbers but expressed satisfaction with the enrollment progress and the reopening of nearly all clinical sites [21][23] Question: Potential impact of COVID-19 on data release timeline - Management indicated that while they are encouraged by current enrollment rates, they must remain cautious about potential COVID-19 disruptions [28][30] Question: Efficacy measures expectations for TORREY study - Management confirmed that expectations for PVR reduction and 6-minute walk improvements remain unchanged [39][40] Question: Differentiation of GB004 in the oral treatment landscape - Management highlighted GB004's unique positioning in the treatment hierarchy for ulcerative colitis, particularly in the mild-to-moderate segment [42] Question: Enrollment pace for GB5121 and study design - Management indicated that the Phase I study for GB5121 is progressing well, focusing on safety and tolerability as primary endpoints [44][45]

Q2:2021 Earnings Update August 2021 Forward Looking Statement 2 This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation, including statements regarding our future results of operations and financial position, business strategy, prospective products, product approvals, research and development costs, timing and likelihood of success, plans and objectives of management for future operations, and future results of current an ...

Financial Data and Key Metrics Changes - The company ended Q2 2021 with cash and cash equivalents of $405.9 million, which is expected to fund operations into the second half of 2023 [37] - Research and development expenses increased to approximately $44.3 million in Q2 2021 from $38.7 million in the same period in 2020 [38] - General and administrative expenses decreased slightly to $11.3 million in Q2 2021 from $11.7 million in Q2 2020 [38] - The net loss for Q2 2021 was $59.8 million, equating to $0.80 per share, compared to a net loss of $66.9 million or $1.00 per share in the same period in 2020 [38] Business Line Data and Key Metrics Changes - The company is focused on two lead clinical programs: Seralutinib and GB004, with Phase 2 data readouts expected in the first half of 2022 [7][8] - Seralutinib is currently enrolling patients in the TORREY study, while GB004 is enrolling in the SHIFT-UC study, both aiming for clinical data in 2022 [8][33] Market Data and Key Metrics Changes - The SHIFT-UC study for GB004 is enrolling 195 patients with active ulcerative colitis, aiming for clinical remission at 12 weeks [8] - The TORREY study for Seralutinib is enrolling 80 patients with pulmonary arterial hypertension, focusing on changes in pulmonary vascular resistance at 24 weeks [9][30] Company Strategy and Development Direction - The company branded 2021 as a year of execution, setting the stage for transformative developments in 2022 [7] - Gossamer Bio is discontinuing clinical activities related to GB1275, focusing resources on the promising Phase 2 programs of Seralutinib and GB004 [35][36] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in the timelines for data readouts despite the ongoing challenges posed by the COVID-19 pandemic [41] - The potential for GB004 to disrupt treatment paradigms in inflammatory bowel disease was highlighted, emphasizing its non-immunosuppressive profile [8][46] Other Important Information - The company plans to present further biomarker analysis from the Phase 1b study of GB004 at the upcoming Virtual European Respiratory Society Meeting [29] - The company is optimistic about the safety profile of GB004 and its potential to be a backbone therapy for IBD patients [46] Q&A Session Summary Question: Current status and pace of enrollment in TORREY and SHIFT-UC - Management refrained from commenting on specific enrollment data but reiterated guidance for top-line data in the first half of 2022 [41] Question: Thoughts on GB004 and payer access - Management believes GB004's non-immunosuppressive approach could position it favorably in the treatment paradigm, potentially appealing to payers [46] Question: Open-label portion for the TORREY study and increasing conversion rates - Management indicated that the TORREY study is designed to be user-friendly and has learned from the Phase 1 experience [52] Question: Focus on oncology in the pipeline - Oncology remains a focus for the company, with several preclinical agents aimed at oncology indications [56] Question: Clinical relevance of improvements in NT-proBNP and 6-minute walk distance - Management emphasized caution in interpreting results from only two patients but found the directionality of the data encouraging [65] Question: Time course of cough during the open-label extension - Cough was predominantly mild and did not lead to discontinuation of the drug [71] Question: Impact on expenses from winding down the GB1275 program - The financial impact is minimal, allowing the company to focus on advancing other programs [72] Question: Timeline for topline data from TORREY or SHIFT-UC - Management maintained that both programs are expected to read out in the first half of 2022 [75]

go frame bio 1 Corporate Presentation February 2021 Forward Looking Statement This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation, including statements regarding our future results of operations and financial position, business strategy, prospective products, product approvals, research and development costs, timing and likelihood of success, plans and objectives of management for future operations, and future results ...

Financial Data and Key Metrics Changes - The company ended 2020 with $512 million in cash and cash equivalents, maintaining a robust balance sheet that is expected to provide sufficient capital resources into the second half of 2023 [11] - R&D expenses for Q4 2020 were $38.9 million, down from $42.6 million in Q4 2019, while full-year R&D expenses increased to $160.9 million from $143.4 million in 2019 [11] - The net loss for Q4 2020 was $64.6 million, or approximately $0.88 per share, compared to a net loss of $54.7 million, or $0.89 per share, in Q4 2019 [12] Business Line Data and Key Metrics Changes - The company is advancing four clinical product candidates: seralutinib (GB002), GB004, GB1275, and GB001, with ongoing Phase II trials for GB002 and GB004 [5][9] - In-process R&D expenses for Q4 2020 were $5.3 million, significantly up from $1.6 million in Q4 2019, primarily due to a $15 million amendment to the in-license agreement of GB004 [11] Market Data and Key Metrics Changes - The company is focusing on severe unmet needs in the PAH and IBD markets, with seralutinib and GB004 targeting these populations [6][8] - The SHIFT-UC study for GB004 is expected to enroll approximately 195 patients with mild to moderate ulcerative colitis, while the TORREY study for seralutinib aims to enroll about 80 PAH patients [7][8] Company Strategy and Development Direction - The company views 2021 as a year of focused execution, with plans to share Phase II top-line data for seralutinib and GB004 in 2022 [5] - The management emphasizes the importance of a robust preclinical pipeline and plans to outline a new clinical program later in the spring [26] Management's Comments on Operating Environment and Future Outlook - Management expressed optimism about the ongoing clinical trials and the potential for transformative treatments in their respective markets [6][10] - The company is taking proactive measures to mitigate the impact of the COVID-19 pandemic on clinical trial timelines and data integrity [36][37] Other Important Information - The company will not advance GB001 into further clinical trials without a partner, indicating a strategic focus on collaboration for future development [10][31] - The management highlighted the importance of safety profiles in their drug candidates, particularly in the context of IBD treatments [40] Q&A Session Summary Question: Can you provide more details on the disease clearance secondary endpoint for GB004? - The management indicated that disease clearance is a new concept and that they expect around 20% or more to be meaningful, but regulatory guidance on this endpoint is still evolving [15][16] Question: What measures are being taken to ensure timelines for the SHIFT-UC study amid COVID-19? - The management mentioned geographic distribution of sites, user-friendly protocols, and strong relationships with investigators as key strategies to ensure timelines are met [19][21] Question: How do you envision the pipeline in 12 to 18 months? - The management anticipates progressing their preclinical pipeline and hopes to outline a new clinical program, aiming for a fifth program to enter the clinic [26][27] Question: What is the status of interactions with regulators regarding GB001? - The management reported constructive interactions with regulators and confirmed a clinical path forward for GB001, but emphasized the need for a partner before advancing to Phase III [30][31] Question: What are the expectations for GB1275 moving forward? - The management indicated that positive Phase I data could lead to exploring other tumor types, but the current focus remains on immuno-oncology [32][33]

go frame bio 1 Corporate Presentation November 2020 Forward Looking Statement This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation, including statements regarding our future results of operations and financial position, business strategy, prospective products, product approvals, research and development costs, timing and likelihood of success, plans and objectives of management for future operations, and future results ...

Start Time: 16:30 January 1, 0000 5:30 PM ET Gossamer Bio, Inc. (NASDAQ:GOSS) Q3 2020 Earnings Conference Call November 10, 2020, 16:30 PM ET Company Participants Sheila Gujrathi - Co-Founder and CEO Bryan Giraudo - CFO Luisa Salter-Cid - Chief Scientific Officer Richard Aranda - SVP, Head of Clinical Development Conference Call Participants Tyler Van Buren - Piper Sandler Joseph Schwartz - SVB Leerink Geoff Meacham - Bank of America Merrill Lynch Josh Schimmer - Evercore ISI Carter Gould - Barclays Emma Ne ...