Gossamer Bio and Chiesi Group Announce Transformative Global Collaboration to Develop and Commercialize Seralutinib in PAH, PH-ILD & Other Indications

Gossamer Bio, Inc. (“Gossamer”) (Nasdaq: GOSS), a clinical-stage biopharmaceutical company focused on the development and commercialization of seralutinib for the treatment of pulmonary hypertension, and Chiesi Farmaceutici S.p.A (“Chiesi Group”), an international, research-focused biopharmaceutical group, today announced that they have entered into a global collaboration and license agreement to develop and commercialize seralutinib.

This global collaboration combines the strengths of both Chiesi and Gossamer to support ongoing work in pulmonary arterial hypertension (PAH) and to accelerate development in pulmonary hypertension associated with interstitial lung disease (PH-ILD), enabling the expansion of the seralutinib franchise to reach more patients with pulmonary hypertension world-wide. Patients will benefit from both Chiesi’s expertise in global respiratory, rare disease, and inhaled drug development and commercialization and Gossamer’s world-class PAH and PH-ILD development and commercialization teams.

“This partnership with Chiesi allows us to meaningfully deepen and rapidly accelerate our investment in seralutinib as a potential treatment for PAH, PH-ILD, and other indications of high unmet medical need,” said Faheem Hasnain, Co-Founder, Chairman and CEO of Gossamer. “We are particularly thrilled that this collaboration enables seralutinib to move directly into a Phase 3 trial in PH-ILD, an indication with a paucity of available treatments, and a disease which we believe seralutinib is specifically designed to address.”

“Seralutinib is a potential paradigm shifting therapy in PAH and PH-ILD, and we could not be more excited to partner with Gossamer to develop and bring this therapy to patients world-wide,” said Giuseppe Accogli, Group CEO of Chiesi. “Gossamer shares Chiesi’s commitment to using innovation to promote the health and well-being of people around the world and we are proud to add this collaboration as a key pillar to our next phase of growth.”

Prevalence estimates vary widely, but PAH is believed to affect approximately 30,000 to 50,000 people in the US, with a similar prevalence in Europe. While many approved PAH treatments are available, most are primarily vasodilators and do not impact the progressive course of the disease. Median 5-year overall survival rate for patients with PAH is approximately 57%. In the past, PH-ILD has not been as readily diagnosed as PAH, in part due to a lack of approved treatment options for these patients. Based on prevalence figures for various forms of ILD and reported rates of PH in ILD patient cohorts, we estimate that PH-ILD affects approximately 60,000-100,000 patients in the US. Patients with PH-ILD in the US have access to only one approved therapy, while no therapies to treat PH-ILD are approved outside of the US. Median 5-year overall survival rate for patients with PH-ILD is approximately 23%.