PART I. FINANCIAL INFORMATION [Item 1. Condensed Consolidated Financial Statements (unaudited)](index=4&type=section&id=Item%201.%20Condensed%20Consolidated%20Financial%20Statements%20(unaudited)) The company reported net losses for Q3 and the nine months ended September 30, 2023, while a July 2023 private placement significantly bolstered its financial position [Condensed Consolidated Balance Sheets](index=4&type=section&id=Condensed%20Consolidated%20Balance%20Sheets) As of September 30, 2023, total assets increased, liabilities decreased, and stockholders' equity turned positive, primarily driven by a recent capital raise Condensed Consolidated Balance Sheet Highlights (in thousands) | Account | Sep 30, 2023 (unaudited) | Dec 31, 2022 | | :--- | :--- | :--- | | Cash and cash equivalents | $82,609 | $111,973 | | Marketable securities | $246,279 | $143,705 | | **Total Assets** | **$347,925** | **$272,450** | | Total current liabilities | $42,316 | $49,230 | | Long-term convertible senior notes | $196,366 | $195,709 | | **Total Liabilities** | **$243,308** | **$260,373** | | **Total Stockholders' Equity** | **$104,617** | **$12,077** | [Condensed Consolidated Statements of Operations and Comprehensive Loss](index=5&type=section&id=Condensed%20Consolidated%20Statements%20of%20Operations%20and%20Comprehensive%20Loss) The company reported reduced net losses for Q3 and the nine months ended September 30, 2023, primarily due to lower research and development and general and administrative expenses Operating Results (in thousands, except per share data) | Metric | Q3 2023 | Q3 2022 | Nine Months 2023 | Nine Months 2022 | | :--- | :--- | :--- | :--- | :--- | | Research and development | $31,200 | $44,509 | $105,334 | $129,411 | | General and administrative | $9,290 | $11,497 | $29,398 | $34,775 | | **Total operating expenses** | **$40,490** | **$56,021** | **$134,732** | **$164,236** | | Loss from operations | ($40,490) | ($56,021) | ($134,732) | ($164,236) | | **Net loss** | **($40,008)** | **($59,363)** | **($131,669)** | **($173,614)** | | Net loss per share, basic and diluted | ($0.21) | ($0.65) | ($1.03) | ($2.14) | [Condensed Consolidated Statements of Cash Flows](index=8&type=section&id=Condensed%20Consolidated%20Statements%20of%20Cash%20Flows) For the nine months ended September 30, 2023, net cash used in operations and investing was offset by significant financing proceeds, leading to a net decrease in cash and cash equivalents Cash Flow Summary (in thousands) | Activity | Nine Months Ended Sep 30, 2023 | Nine Months Ended Sep 30, 2022 | | :--- | :--- | :--- | | Net cash used in operating activities | ($125,734) | ($139,302) | | Net cash used in investing activities | ($96,604) | ($9,499) | | Net cash provided by financing activities | $193,057 | $119,963 | | **Net decrease in cash and cash equivalents** | **($29,364)** | **($29,990)** | [Notes to Unaudited Condensed Consolidated Financial Statements](index=9&type=section&id=Notes%20to%20Unaudited%20Condensed%20Consolidated%20Financial%20Statements) Key notes detail the company's clinical-stage biopharmaceutical business, significant accumulated deficit, recent private placement proceeds, existing debt, and employee stock option repricing - The company is a clinical-stage biopharmaceutical firm focused on immunology, inflammation, and oncology, with a historical record of significant operating losses and an accumulated deficit of **$1.16 billion** as of September 30, 2023[24](index=24&type=chunk)[26](index=26&type=chunk) - In July 2023, the company completed a private placement of common stock and warrants, raising approximately **$212.1 million** in gross proceeds (**$201.3 million** net) Management believes current capital is sufficient to fund operations for at least the next 12 months[27](index=27&type=chunk)[28](index=28&type=chunk) - In May 2023, the company repriced 6,817,057 outstanding employee stock options to an exercise price of **$1.36 per share**, resulting in **$3.4 million** of incremental stock-based compensation cost[81](index=81&type=chunk)[84](index=84&type=chunk) Indebtedness Summary (in thousands) | Debt Instrument | Net Carrying Amount (Sep 30, 2023) | | :--- | :--- | | Credit Facility | $15,247 | | 5.00% Convertible Senior Notes due 2027 | $196,366 | [Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations](index=23&type=section&id=Item%202.%20Management%27s%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) Management discusses the company's focus on seralutinib development, reduced operating expenses, and the sufficiency of its capital, bolstered by a July 2023 private placement, to fund operations for at least 12 months [Overview](index=24&type=section&id=Overview) The company, a clinical-stage biopharmaceutical firm, primarily focuses on developing seralutinib for PAH, with a Phase 3 study commencing in Q4 2023, and anticipates continued losses given its significant accumulated deficit - The company's primary focus is on developing seralutinib for the treatment of pulmonary arterial hypertension (PAH)[102](index=102&type=chunk) - The Phase 3 PROSERA study for seralutinib is expected to dose its first PAH patient in Q4 2023 Clinical development for pulmonary hypertension associated with interstitial lung disease is planned for H1 2024[102](index=102&type=chunk) - As of September 30, 2023, the company had **$328.9 million** in cash, cash equivalents, and marketable securities and an accumulated deficit of **$1,163.9 million**[104](index=104&type=chunk)[105](index=105&type=chunk) [Results of Operations](index=28&type=section&id=Results%20of%20Operations) Operating expenses decreased for both the three and nine-month periods ended September 30, 2023, primarily due to lower R&D costs from terminated programs and reduced general and administrative expenses - R&D expenses for Q3 2023 decreased by **$13.3 million** year-over-year, primarily due to reduced costs for GB5121 and other terminated programs, partially offset by a **$9.2 million** increase in spending on seralutinib[119](index=119&type=chunk) - General and administrative expenses for Q3 2023 decreased by **$2.2 million** year-over-year, mainly due to a **$1.6 million** decrease in stock-based compensation expense[123](index=123&type=chunk) Research and Development Expenses by Program (in thousands) | Program | Q3 2023 | Q3 2022 | Nine Months 2023 | Nine Months 2022 | | :--- | :--- | :--- | :--- | :--- | | Seralutinib | $27,010 | $17,855 | $67,149 | $43,326 | | GB5121 | $1,815 | $14,477 | $22,473 | $38,013 | | Other programs | $2,375 | $7,873 | $15,175 | $25,091 | | Other terminated programs | $0 | $4,304 | $537 | $22,981 | | **Total R&D** | **$31,200** | **$44,509** | **$105,334** | **$129,411** | [Liquidity and Capital Resources](index=29&type=section&id=Liquidity%20and%20Capital%20Resources) The company has historically funded operations through equity and debt, raising $1.26 billion through September 2023, and believes its current capital, bolstered by a July 2023 private placement, is sufficient for at least the next 12 months - Operations have been financed by **$1.26 billion** raised from inception through September 30, 2023, via stock and debt offerings[130](index=130&type=chunk) - In July 2023, a private placement of common stock and warrants raised gross proceeds of **$212.1 million**[136](index=136&type=chunk) - The company believes its existing cash, cash equivalents, and marketable securities of **$328.9 million** are sufficient to fund operations for at least the next 12 months[130](index=130&type=chunk)[145](index=145&type=chunk) [Item 3. Quantitative and Qualitative Disclosures About Market Risk](index=31&type=section&id=Item%203.%20Quantitative%20and%20Qualitative%20Disclosures%20About%20Market%20Risk) There have been no material changes to the company's market risk disclosures since its Annual Report on Form 10-K for the year ended December 31, 2022 - There have been no material changes in the company's market risk profile since the fiscal year ended December 31, 2022[148](index=148&type=chunk) [Item 4. Controls and Procedures](index=32&type=section&id=Item%204.%20Controls%20and%20Procedures) Management concluded that disclosure controls and procedures were effective as of September 30, 2023, with no material changes in internal control over financial reporting during the quarter - Management concluded that as of September 30, 2023, the company's disclosure controls and procedures were effective at the reasonable assurance level[150](index=150&type=chunk) - No changes occurred in the company's internal control over financial reporting during Q3 2023 that have materially affected, or are reasonably likely to materially affect, these controls[151](index=151&type=chunk) PART II. OTHER INFORMATION [Item 1. Legal Proceedings](index=33&type=section&id=Item%201.%20Legal%20Proceedings) The company is not currently subject to any material legal proceedings, though it may be involved in ordinary course legal matters - The company is not currently a party to any material legal proceedings[154](index=154&type=chunk) [Item 1A. Risk Factors](index=33&type=section&id=Item%201A.%20Risk%20Factors) A new risk factor highlights the potential delisting of the company's common stock from Nasdaq due to failing the minimum bid price requirement, with a compliance deadline of April 16, 2024 - On October 19, 2023, the company received a notice from Nasdaq because its common stock bid price had closed below the minimum **$1.00 per share** requirement for **30 consecutive business days**[155](index=155&type=chunk) - The company has an initial period of **180 calendar days**, until April 16, 2024, to regain compliance by having its stock close at or above **$1.00** for at least **10 consecutive business days**[155](index=155&type=chunk) - Failure to regain compliance could result in delisting, which would negatively affect the stock price, impair liquidity, and hinder future financing efforts[156](index=156&type=chunk) [Item 2. Unregistered Sales of Equity Securities and Use of Proceeds](index=33&type=section&id=Item%202.%20Unregistered%20Sales%20of%20Equity%20Securities%20and%20Use%20of%20Proceeds) No unregistered sales of equity securities or issuer repurchases of equity securities occurred during the period - None reported[157](index=157&type=chunk)[158](index=158&type=chunk) [Item 3. Defaults Upon Senior Securities](index=33&type=section&id=Item%203.%20Defaults%20Upon%20Senior%20Securities) This section is not applicable - Not Applicable[159](index=159&type=chunk) [Item 4. Mine Safety Disclosures](index=34&type=section&id=Item%204.%20Mine%20Safety%20Disclosures) This section is not applicable - Not Applicable[160](index=160&type=chunk) [Item 5. Other Information](index=34&type=section&id=Item%205.%20Other%20Information) No other information is reported in this section - None[161](index=161&type=chunk) [Item 6. Exhibits](index=34&type=section&id=Item%206.%20Exhibits) This section references the Exhibit Index, listing all exhibits filed or furnished as part of the Quarterly Report on Form 10-Q - The report includes an Exhibit Index listing all filed or furnished exhibits[162](index=162&type=chunk)

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q _________________________ ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________to_________. Commission File Number: 001-38796 GOSSAMER BIO, INC. (Exact name of Registrant as specified in its charte ...

Table of Contents WASHINGTON, D.C. 20549 _________________________ FORM 10-Q _________________________ ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 UNITED STATES SECURITIES AND EXCHANGE COMMISSION For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________to_________. Commission File Number: 001-38796 GOSSAMER BIO, INC. (Exact name of Registrant ...

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 ...