Gossamer Bio

Gossamer Bio, Inc. is a San Diego-based, late-stage clinical biopharmaceutical company established in 2017. The company was co-founded by Faheem Hasnain and Sheila Gujrathi, M.D., both former executives from Receptos, Inc., a company acquired by Celgene in 2015 for $7.2 billion. Their shared experience in immunology and successful track record in drug development formed the foundation for Gossamer, which launched with an initial $100 million in capital from a Series A financing round co-led by ARCH Venture Partners and Omega Funds. The company's initial strategy focused on in-licensing and developing assets in immunology, inflammation, and oncology. A significant milestone was achieved in February 2019 when Gossamer Bio went public on the Nasdaq (GOSS), raising approximately $276 million in its initial public offering to fund its clinical programs.

As a clinical-stage entity, Gossamer Bio's business model is centered on intensive research and development, funded by equity financing and strategic partnerships. The company does not generate revenue from direct product sales but through collaboration and licensing agreements. A key partnership is a global collaboration with Chiesi Group for the development and commercialization of its lead product candidate. Under this agreement, Gossamer received a $160 million development reimbursement and is eligible for further milestone payments, while planning to share U.S. commercial profits and losses and receive royalties on ex-U.S. sales. As of June 30, 2025, the company reported having cash, cash equivalents, and marketable securities of $212.9 million, which is expected to fund operations into 2027.

Gossamer's primary focus is the development and commercialization of seralutinib for the treatment of pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH-ILD). Seralutinib is an inhaled small molecule designed to inhibit multiple tyrosine kinases (PDGFRα/β, CSF1R, and c-KIT) that are involved in the abnormal cell growth driving PAH. This targeted delivery via a dry powder inhaler aims to maximize efficacy at the site of the disease while minimizing systemic side effects. The company is conducting the PROSERA Study, a global, registrational Phase 3 clinical trial for seralutinib in PAH patients, with topline results anticipated in February 2026. Enrollment for this study was completed in June 2025. Additionally, a Phase 3 trial, SERANATA, is planned to investigate seralutinib in PH-ILD, with site activations expected in late 2025.

Keywords: seralutinib, pulmonary arterial hypertension, PAH, Gossamer Bio, clinical-stage biopharmaceutical, Faheem Hasnain, Sheila Gujrathi, Chiesi Group, pulmonary hypertension associated with interstitial lung disease, PH-ILD, inhaled therapy, tyrosine kinase inhibitor, PDGFR inhibitor, CSF1R inhibitor, c-KIT inhibitor, PROSERA study, SERANATA study, GOSS, clinical trials, orphan drug, drug development, biopharma, life sciences