Gossamer and Chiesi Collaborate to Develop Pulmonary Therapy

Rare Daily Staff

Gossamer Bio and Chiesi Farmaceutici have entered into a global collaboration and license agreement to develop and commercialize seralutinib to address rare, pulmonary diseases.

The collaboration will 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.

“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. “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.”

PAH and PH-ILD are rare, serious, progressive pulmonary diseases. While many approved PAH treatments are available, most are primarily vasodilators and do not impact the progressive course of the disease. Median five-year overall survival rate for patients with PAH is approximately 57 percent.

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. Patients with PH-ILD in the United States have access to only one approved therapy, while no therapies to treat PH-ILD are approved outside of the United States. Median five-year overall survival rate for patients with PH-ILD is approximately 23 percent.

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 need.

“Seralutinib is a potential paradigm shifting therapy in PAH and PH-ILD,” said Giuseppe Accogli, Group CEO of Chiesi.

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 United States, the companies will evenly share commercial profits and losses. Gossamer will lead commercialization and book sales for PAH and PH-ILD in the United States, with both companies contributing 50 percent of commercial efforts. Chiesi will lead U.S. commercialization in additional indications.

Chiesi will have the exclusive right to commercialize seralutinib outside of the U.S. and will pay Gossamer an escalating mid-to-high teens royalty on net sales. 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.

Photo: Faheem Hasnain, co-founder, chairman and CEO of Gossamer