Gossamer Bio — Third Quarter 2026 Earnings Summary

Financial Performance:

• Revenue from contracts with collaborators was $38.4 million for the quarter ended September 30, 2026, compared to $13.3 million in the same period in 2025, an increase of $25.1 million primarily driven by revenue recognized upon the termination of the Chiesi Collaboration Agreement.
• Research and Development (R&D) expenses were $18.8 million for the quarter, down from $45.5 million in the same period in 2025, driven by a $15.7 million decrease in clinical trial costs for seralutinib.
• General and Administrative (G&A) expenses were $9.6 million for the quarter, compared to $9.4 million in the same period in 2025.
• Net loss for the quarter was $48.1 million ($7.36 per share), compared to a net loss of $48.2 million ($16.92 per share) in the same period in 2025.
• Cash, cash equivalents, and marketable securities totaled $51.2 million as of September 30, 2026, compared to $57.0 million as of June 30, 2026.
• Total operating expenses were $31.2 million for the quarter, compared to $62.4 million in the same period in 2025.
• Loss from operations was $7.2 million for the quarter, compared to a loss of $49.1 million in the same period in 2025.
• Other income (expense), net, was $(55.3) million for the quarter, primarily driven by a $(56.5) million remeasurement of warrant liability and $(2.5) million in interest expense.
• For the nine months ended September 30, 2026, total revenue was $64.6 million compared to $34.7 million in the prior year period.
• For the nine months ended September 30, 2026, net loss was $77.8 million compared to $123.1 million in the prior year period.

Guidance and Future Outlook:

• Management aims to prepare for a potential commercial launch of seralutinib in 2027.
• The company remains focused on supporting the FDA's review of the submitted NDA.
• FDA acceptance of the NDA in 2026 is expected to unlock up to approximately $125 million in additional committed capital, subject to customary closing conditions.

Business Segments and Product Lines:

• Seralutinib (GB002), an inhaled PDGFRα/β, CSF1R, and c-KIT inhibitor, is the company's primary asset for the treatment of pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH-ILD).
• The company submitted its first New Drug Application (NDA) for seralutinib in PAH to the U.S. FDA in September 2026.
• The NDA is supported by the Phase 3 PROSERA Study, confirmatory evidence from the Phase 2 TORREY Study, and additional supportive analyses.
• In July 2026, Gossamer reacquired worldwide development and commercial rights to seralutinib from Chiesi Farmaceutici S.p.A., terminating their prior collaboration.
• The reacquisition agreement included a one-time $5 million payment from Chiesi with no upfront cash payment by Gossamer; Chiesi retains rights to capped royalties and certain regulatory and commercial milestone payments.

Market and Competitive Landscape:

• Seralutinib remains investigational and has not been approved by any regulatory authority.
• The company's goal is to become an industry leader in enhancing the lives of patients living with pulmonary hypertension.

Risks and Challenges:

• Key risks include the possibility that the FDA may not accept or approve the NDA for seralutinib.
• Contingent financing milestones or closing conditions for the private placement may not be achieved.
• The Company may not receive anticipated proceeds or additional capital may not be available on reasonable terms.
• Clinical, regulatory, manufacturing, or commercial timelines may be delayed.

Management Commentary and Tone:

• Faheem Hasnain, Chairman, Co-Founder, and CEO, stated that submitting the first NDA marks an important milestone in efforts to bring seralutinib to patients.
• Management expressed confidence that FDA acceptance would unlock capital to support priorities including preparations for a potential launch.
• The tone indicates a focus on regulatory review and commercial preparation for 2027.

Other Key Points:

• A structured private placement announced in August 2026 offers total potential gross proceeds of up to approximately $250 million.
• The initial closing of the private placement provided approximately $25 million in gross proceeds.
• A second closing provides up to approximately $125 million in additional gross proceeds contingent on FDA acceptance of the NDA in 2026.
• Warrants related to FDA approval could provide up to approximately $100 million of additional gross proceeds, contingent on FDA approval and cash exercise of the warrants.
• Gossamer completed a 1-for-80 reverse stock split in September 2026 to regain compliance with Nasdaq minimum bid price requirements, with split-adjusted trading commencing under the symbol "GOSS".
• The company reported a remeasurement of warrant liability of $(56.5) million and a remeasurement of derivative liability of $5.6 million for the quarter.
• A gain on debt extinguishment of $43.8 million was recorded for the nine months ended September 30, 2026.