Gossamer Bio Secures Up to $250 Million for Seralutinib

Gossamer Bio has entered into an agreement with new and existing institutional investors to raise up to approximately $250 million through a private placement. The funding will support the development of seralutinib, the company’s experimental treatment for pulmonary arterial hypertension (PAH).

The financing comes shortly after Gossamer Bio reacquired worldwide rights to seralutinib and ahead of the company’s planned submission of a New Drug Application (NDA) to the US Food and Drug Administration (FDA) in September 2026.

The private placement includes $150 million in committed funding. Around $25 million is expected to be provided at the initial closing, while an additional $125 million will be available at a second closing if the FDA accepts Gossamer’s seralutinib NDA for review.

The second funding round is dependent on the FDA accepting the NDA in 2026, along with other standard closing conditions. If the regulatory milestone is achieved, Gossamer expects to receive the full $150 million in committed capital during 2026.

The financing also includes warrants that can be exercised if seralutinib receives FDA approval for PAH. Together with the committed funding and potential warrant proceeds, the financing could provide Gossamer with gross proceeds of up to approximately $250 million before fees and other offering expenses.

Several institutional healthcare investors are participating in the financing. These include EcoR1 Capital, 683 Capital Partners, RA Capital Management, Coastlands Capital, Samsara BioCapital and Rock Springs Capital, among others.

Seralutinib is being developed as a potential treatment for PAH, a serious condition in which the blood vessels in the lungs become narrowed, making it harder for the heart to pump blood through the lungs. Gossamer is also developing the drug for pulmonary hypertension associated with interstitial lung disease (PH-ILD).

The company said the new funding is expected to provide the financial resources needed to advance seralutinib toward a potential FDA approval in PAH. The financing structure also links additional capital to important regulatory milestones.

Faheem Hasnain, Chairman, Co-Founder and Chief Executive Officer of Gossamer Bio, said the funding is expected to support the company’s planned NDA submission and the FDA review process.

Gossamer plans to submit the seralutinib NDA in September 2026. The company hopes the treatment could become a new option for patients with PAH, while continuing development in other forms of pulmonary hypertension.