Gossamer Bio Reports Second-Quarter 2026 Results and Advances Seralutinib Toward Planned FDA Submission
Gossamer Bio, Inc., a clinical-stage biopharmaceutical company focused on developing and potentially commercializing therapies for pulmonary vascular and respiratory diseases, has announced its financial results for the second quarter ended June 30, 2026, along with a business update highlighting significant progress for its lead investigational medicine, seralutinib.
The company is developing seralutinib (GB002) for the treatment of pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH-ILD). During the second quarter, Gossamer reached several important corporate and regulatory milestones, including completing a Pre-New Drug Application (NDA) Type B meeting with the U.S. Food and Drug Administration (FDA), receiving the official meeting minutes and confirming its plan to submit an NDA for seralutinib in PAH in September 2026.
The company also strengthened its strategic position by reacquiring worldwide development and commercial rights to seralutinib from Chiesi and completing a major convertible note exchange that substantially reduced its outstanding debt.
“We have worked hard to strengthen Gossamer and prepare the Company for what comes next,” said Faheem Hasnain, Chairman, Co-Founder and CEO of Gossamer. “We completed a productive Pre-NDA Type B meeting with the FDA, received the official minutes and remain on track to submit our NDA for seralutinib in PAH in September. We also reacquired worldwide rights to seralutinib and completed a convertible note exchange that substantially reduced our debt.”
Hasnain added that Gossamer is now in a stronger position and remains focused on advancing seralutinib through the regulatory process.
Seralutinib Remains the Company’s Central Development Program
Seralutinib, also known as GB002, is an inhaled investigational therapy designed to inhibit platelet-derived growth factor receptor (PDGFR), colony-stimulating factor 1 receptor (CSF1R) and c-KIT. Gossamer is evaluating the therapy as a potential treatment for pulmonary vascular diseases, particularly PAH and PH-ILD.
PAH is a serious and progressive condition characterized by increased pressure in the pulmonary arteries. The disease can place significant strain on the right side of the heart and may ultimately lead to heart failure. Existing therapies primarily target pathways involved in pulmonary vasoconstriction and vascular remodeling, while research into novel approaches continues to seek treatments that can address underlying disease processes more broadly.
Gossamer’s development strategy for seralutinib is based on its potential to target pathways associated with abnormal cellular activity and vascular remodeling. The company is advancing the program toward a regulatory submission in PAH following clinical data generated in its development program.
FDA Pre-NDA Meeting Supports Planned September Filing
One of the most important developments during the quarter was Gossamer’s interaction with the FDA.
The company held a Pre-NDA Type B meeting with the FDA in mid-June 2026 to discuss its planned regulatory submission for seralutinib. Gossamer has since received the official minutes documenting the FDA’s feedback from the meeting.
According to Gossamer, the FDA characterized questions concerning the statistical significance and magnitude of the treatment effect observed in the Phase 3 PROSERA study as review issues rather than filing issues. The agency also provided feedback regarding the structure, format and content of the proposed NDA.
Based on the FDA meeting and the subsequent official minutes, Gossamer plans to submit an NDA for seralutinib in PAH in September 2026.
The proposed application is expected to be supported primarily by the Phase 3 PROSERA study, described by the company as one adequate and well-controlled study, together with confirmatory evidence from the Phase 2 TORREY study and additional supportive analyses.
If the FDA accepts the application for review, Gossamer expects that seralutinib could potentially receive an FDA approval decision during the third quarter of 2027.
However, the company emphasized that the FDA’s comments during the Pre-NDA meeting should not be interpreted as a determination that the therapy will ultimately be approved. The agency will make its final assessment of seralutinib’s approvability after reviewing the complete NDA and all supporting information.
Gossamer Reacquires Worldwide Rights to Seralutinib
Gossamer also announced a major strategic change involving the global rights to seralutinib.
The company and Chiesi have agreed to terminate their existing Collaboration and License Agreement, allowing Gossamer to reacquire worldwide development and commercial rights to seralutinib ahead of the planned NDA filing.
The agreement gives Gossamer greater control over the future of seralutinib, including development strategy, manufacturing, commercialization, pricing and lifecycle management across global markets.
Under the previous arrangement, Gossamer and Chiesi maintained a 50/50 U.S. profit-sharing structure, while Chiesi held rights outside the United States. The termination of the collaboration eliminates the previous U.S. profit-sharing arrangement and returns ex-U.S. rights to Gossamer.
As part of the termination agreement, Chiesi is required to make a one-time $5 million payment to Gossamer. The payment settles outstanding and future obligations under the previous collaboration, including costs associated with the second quarter of 2026.
Importantly, Gossamer did not make an upfront cash payment to reacquire the global rights.
Instead, Chiesi will receive a capped royalty on worldwide net sales of seralutinib, with no additional royalty obligations once the agreed cap is reached. Chiesi will also be eligible for payments tied to specified regulatory and commercial milestones.
The transaction therefore provides Gossamer with a substantially greater share of the potential long-term economics associated with seralutinib while giving the company full control over the asset.
Stockholders Approve Convertible Note Exchange and Reverse Stock Split Authorization
Gossamer also reported progress in strengthening its financial position.
At a special meeting held on July 14, 2026, stockholders approved proposals related to the company’s previously completed exchange of its 5.00% Convertible Senior Notes due 2027 and authorized the company’s Board of Directors to implement a reverse stock split.
The convertible note exchange represented a significant reduction in Gossamer’s outstanding debt.
The company exchanged approximately $181.1 million, representing 90.5% of the $200 million aggregate principal amount of its outstanding 2027 Notes, for approximately $65.2 million of new 7.50% Convertible Senior Secured First Lien Notes due 2030, in addition to equity securities and warrants.
As a result, Gossamer reduced the aggregate principal amount of its debt by approximately $115.9 million. Following the exchange, approximately $18.9 million of the original 2027 Notes remained outstanding.
The stockholder approval also provides the Board with authorization to implement a reverse stock split. The timing and final ratio of any reverse stock split remain subject to Board approval.
The debt restructuring is an important component of Gossamer’s efforts to strengthen its balance sheet as it moves toward the planned regulatory submission for seralutinib.
Second-Quarter Financial Performance
Gossamer ended the second quarter with $57.0 million in cash, cash equivalents and marketable securities as of June 30, 2026.
Based on its current financial position and expected expenditures, the company anticipates that its existing cash, cash equivalents and marketable securities will be sufficient to fund operating and capital expenditures into the first quarter of 2027.
The company also reported revenue associated with its collaboration with Chiesi of $9.2 million for the quarter. This included $6.1 million in cost reimbursement revenue. By comparison, collaboration-related revenue totaled $11.5 million during the same quarter of 2025.
Gossamer’s research and development expenses declined substantially year over year. R&D expenses were $26.4 million for the second quarter of 2026, compared with $41.6 million during the second quarter of 2025.
The reduction was primarily attributed to lower costs associated with seralutinib clinical trials as certain development activities progressed.
General and administrative expenses were relatively stable, totaling $8.9 million in the second quarter of 2026 compared with $8.7 million during the same period in 2025.
Improved Net Income Position
Gossamer reported net income of $16.9 million for the second quarter of 2026. The company reported basic net income of $0.05 per share and diluted net loss of $0.08 per share.
This compares with a net loss of $38.3 million during the second quarter of 2025, when the company reported basic and diluted net losses of $0.17 per share.
The improvement reflects changes in the company’s financial and operating profile, including collaboration-related revenue and lower research and development expenses.
Positioning for the Next Stage of Seralutinib Development
Gossamer enters the second half of 2026 with its attention increasingly focused on the planned NDA submission for seralutinib in PAH.
The combination of regulatory discussions with the FDA, reacquisition of worldwide rights and substantial debt reduction has reshaped the company’s strategic position. If Gossamer successfully submits its NDA in September and the application is accepted for review, the company could move into a potentially important regulatory period extending into 2027.
The company’s near-term priorities will include completing the NDA submission, continuing to engage with regulatory authorities and preparing for potential commercialization activities should seralutinib ultimately receive approval.
At the same time, Gossamer remains focused on the broader development potential of seralutinib in pulmonary vascular disease, including PH-ILD.
For patients and healthcare providers, new therapeutic options remain an important need in pulmonary hypertension, particularly for diseases associated with progressive vascular and lung changes. Gossamer believes seralutinib’s mechanism and clinical development program could potentially provide a differentiated treatment option if successfully developed and approved.
With a strengthened balance sheet, full worldwide rights to its lead asset and a planned regulatory submission approaching, Gossamer Bio is positioning itself for a pivotal period in the development of seralutinib. The company’s second-quarter results demonstrate its efforts to reduce financial obligations while concentrating resources on the regulatory and clinical advancement of its lead program.
About Gossamer Bio
Gossamer Bio is a clinical-stage biopharmaceutical company focused on the development and commercialization of seralutinib for the treatment of pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease. Its goal is to be an industry leader in, and to enhance the lives of patients living with, pulmonary hypertension.