The Italian pharma will gain access to Gossamer Bio’s candidate seralutinib, which reached its primary endpoint in a Phase II pulmonary arterial hypertension trial in 2022 and started a Phase III study last year.
Italian pharma Chiesi Group announced Monday that it has signed a potential $486 million global collaboration and licensing deal with Gossamer Bio to develop the pulmonary arterial hypertension treatment seralutinib.
Under the deal, Gossamer will lead the global development of seralutinib in pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH-ILD). The drug is a PDGFRα/β, CSF1R, and c-KIT inhibitor that delivers a dry powder via an inhaler.
San Diego-based biotech Gossamer will receive $160 million in development reimbursement and is eligible to receive up to $146 million in regulatory and $180 million in sales milestones. The biotech will also take the lead on commercialization and booking sales for the drug in PAH and PH-ILD in the U.S., with both companies providing 50% of the commercial efforts.
Chiesi will lead the drug’s commercialization in the U.S. for other indications and get the exclusive rights to seralutinib outside of the U.S. The pharma will pay Gossamer an “escalating mid-to-high teens” royalty on net sales as well. Chiesi and Gossamer will split the development costs for the drug except the biotech is financially responsible for a Phase III trial of seralutinib in patients with PAH. The companies plan to initiate a global Phase III registrational study in PH-ILD in mid-2025.
“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,” Gossamer CEO Faheem Hasnain said in a statement. “We are particularly thrilled that this collaboration enables seralutinib to move directly into a Phase III trial in PH-ILD, an indication with a paucity of available treatments, and a disease which we believe seralutinib is specifically designed to address.”
Gossamer started seralutinib’s Phase III PAH trial last year after reaching its primary endpoint in a Phase II study in 2022. The Phase II study’s primary endpoint was a change from baseline to week 24 in pulmonary vascular resistance, a primary cause of pulmonary hypertension. However, the study did not reach the secondary endpoint of a six-minute walk distance, and both endpoints failed to meet statistical significance.
The six-minute walk distance is also a major point of investigation in the Phase III study. Nevertheless, Chiesi and Gossamer remain bullish about patients’ response to the drug and are optimistic about future development.
“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,” Chiesi Group CEO Giuseppe Accogli said in a statement.
Seralutinib’s development comes on the heels of Merck winning approval for Winrevair, the first FDA-approved activin signaling inhibitor for PAH, in March 2024. The drug targets an underlying cause of the disease. Merck gained access to Winrevair after acquiring Acceleron Pharma for $11.5 billion in 2021.
Tyler Patchen is a staff writer at BioSpace. You can reach him at tyler.patchen@biospace.com. Follow him on LinkedIn.
