Gossamer Bio Announces Fourth Quarter and Full-Year 2019 Financial Results and Provides Business Update - Clinical trial results for all four clinical-stage product candidates in target areas of immunology, inflammation

Gossamer Bio Announces Fourth Quarter and Full-Year 2019 Financial Results and Provides Business Update

- Clinical trial results for all four clinical-stage product candidates in target areas of immunology, inflammation and oncology expected in 2020 -

- Cash, cash equivalents and marketable securities totaled $401.8 million at year-end 2019 -

SAN DIEGO-(BUSINESS WIRE)-March 24, 2020-Gossamer Bio, Inc. (Nasdaq: GOSS), a clinical-stage biopharmaceutical company focused on discovering, acquiring, developing and commercializing therapeutics in the disease areas of immunology, inflammation and oncology, today announced its financial results for the fourth quarter and year ended December 31, 2019 and provided a business update.

"Our hearts are with the patients, families, caregivers and medical professionals suffering and sacrificing in the ongoing Covid-19 viral pandemic. We are monitoring the situation on a daily basis to understand the impact on Gossamer and our programs and are taking the necessary actions now to do what is best for our patients, employees and company," said Sheila Gujrathi, M.D., Co-Founder and Chief Executive Officer of Gossamer Bio.

"2019 was a year of execution for Gossamer Bio, as we continued to advance all four of our clinical-stage product candidates in our target areas of immunology, inflammation and oncology. Notwithstanding the Covid-19 pandemic, we expect to continue our momentum in 2020, with data from all of our candidates expected this year. We are committed to advancing our product candidates and the field of medicine for the betterment of patients and their families, and we look forward to providing updates on these efforts throughout the year."

Clinical-Stage Product Candidate Updates

GB001: Oral DP2 Antagonist for Eosinophilic Asthma and Chronic Rhinosinusitis (CRS)

GB002: Inhaled PDGFR Inhibitor for Pulmonary Arterial Hypertension (PAH)

GB004: Oral HIF-1 Stabilizer for Inflammatory Bowel Disease

GB1275: Oral CD11b Modulator for Oncology Indications

Financial Results for Quarter and Full Year Ended December 31, 2019

Gossamer Bio is a clinical-stage biopharmaceutical company focused on discovering, acquiring, developing and commercializing therapeutics in the disease areas of immunology, inflammation and oncology. Its goal is to be an industry leader in each of these therapeutic areas and to enhance and extend the lives of patients suffering from such diseases.

Forward-Looking Statements

Gossamer cautions you that statements contained in this press release regarding matters that are not historical facts are forward-looking statements. These statements are based on the Company's current beliefs and expectations. Such forward-looking statements include, but are not limited to, statements regarding the anticipated timing of initiation and enrollment of clinical trials for our product candidates; plans to rapidly advance our product candidates; expectations on the timing of data readouts from our clinical studies; the potential clinical benefits of our product candidates; the indications we intend to pursue and our related business strategies; the expected timeframe for funding our operating plan with current cash, cash equivalents and marketable securities; and access to the Company's senior debt facility. The inclusion of forward-looking statements should not be regarded as a representation by Gossamer that any of its plans will be achieved. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in Gossamer's business, including, without limitation: potential delays in the commencement, enrollment and completion of clinical trials; disruption to our operations from the recent global outbreak of the Covid-19 pandemic; the Company's dependence on third parties in connection with product manufacturing, research and preclinical and clinical testing; the success of Gossamer's clinical trials and preclinical studies for its product candidates; regulatory developments in the United States and foreign countries; unexpected adverse side effects or inadequate efficacy of the Company's product candidates that may limit their development, regulatory approval and/or commercialization, or may result in recalls or product liability claims; Gossamer's ability to obtain and maintain intellectual property protection for its product candidates; Gossamer's ability to comply with its obligations in collaboration agreements with third parties or the agreements under which it licenses intellectual property rights from third parties; the risk that the funding under the senior debt facility may not be completed on the timeframe Gossamer expects, or at all, including as a result of Gossamer's failure to meet the conditions required for such funding or failure to comply with the affirmative and negative covenants under the credit facility; and other risks described in the Company's prior press releases and the Company's filings with the Securities and Exchange Commission (SEC), including under the heading "Risk Factors" in the Company's annual report on Form 10-K and any subsequent filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Gossamer undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

CONDENSED CONSOLIDATED FINANCIAL STATEMENT DATA

(UNAUDITED; IN THOUSANDS, EXCEPT SHARE AND PER SHARE DATA)

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