Chiesi Farmaceutici S.p. A Gossamer Bio, Inc. 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), with the aim of expanding 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. 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.