Chiesi Farmaceutici S.p.A, an international, research-focused biopharmaceutical group, and Gossamer Bio, Inc., a clinical-stage biopharmaceutical company focused on the development and commercialization of seralutinib for the treatment of pulmonary hypertension, have entered into a global collaboration and license agreement to develop and commercialize seralutinib.
 
This 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), with the aim of expanding the seralutinib franchise to reach more patients with pulmonary hypertension worldwide.
 
“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 worldwide,” said Giuseppe Accogli, CEO of Chiesi Group.
 
“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,” added 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.”

Evaluating Seralutinib for Additional Indications

Seralutinib is an inhaled PDGFRα/β, CSF1R, and c-KIT inhibitor designed to be delivered via dry powder inhaler for the potential treatment of pulmonary hypertension. Following the positive readout of the Phase 2 TORREY Study in patients with PAH, Gossamer initiated the Phase 3 PROSERA Study in 2023.
 
Gossamer and Chiesi plan to initiate a global Phase 3 registrational study in PH-ILD in mid-2025 and to evaluate seralutinib in additional indications of high unmet medical need.

Terms of the Agreement

Under the terms of the agreement, Gossamer will continue to lead global development of seralutinib in PAH and PH-ILD, and the companies will evenly split development costs, except with respect to the PROSERA Study, for which Gossamer will remain financially responsible.
 
In the US, the companies will evenly share commercial profits and losses. Gossamer will lead US commercialization, including contributing 50 percent of commercial activities and booking of sales for PAH and PH-ILD. Chiesi will lead US commercialization for additional indications. Chiesi will have the exclusive right to commercialize seralutinib outside of the US and will pay Gossamer an escalating mid-to-high teens royalty on net sales outside of the US.
 
Chiesi will pay Gossamer $160 million as a development reimbursement. Additionally, Gossamer will be eligible to receive up to $146 million in regulatory milestones and $180 million in sales milestones.