Gossamer and Chiesi Join Forces for the Development of Their Pulmonary Arterial Hypertension (PAH) Drug

Gossamer Bio, a clinical-stage biopharmaceutical company, announced its collaboration with the Italian research-focused biopharmaceutical group Chiesi. The deal is focused on the commercialization and development of Gossamer’s pulmonary arterial hypertension (PAH) drug, seralutinib.

Designed to be inhaled and delivered via a dry powder inhaler, seralutinib works as a treatment for pulmonary hypertension by acting as a CSF1R, c-KIT, and PDGFRα/β inhibitor.

Last year, Gossamer initiated a Phase 3 PROSERA Study for the drug, especially motivated by the positive results the drug showed in the Phase 2 TORREY Study in patients with PAH. Under the terms of the agreement for this deal, Gossamer will continue to bear the entire financial responsibility for this trial.

The company will also continue to lead in terms of developmental responsibility for seralutinib in PAH and PH-ILD. However, in this case, both Gossamer and Chiesi will evenly split the expenses incurred.

Coupled with their exciting focus on developing seralutinib as a treatment for pulmonary hypertension, the intention of this global collaboration is to take things a step further to allow the development of the drug in pulmonary hypertension associated with interstitial lung disease (PH-ILD) as well. The goal is to expand the seralutinib franchise in the pulmonary hypertension field globally.

Both Giuseppe Accogli, CEO of Chiesi Group, and Faheem Hasnain, Co-Founder, Chairman, and CEO of Gossamer, have expressed their delight over the partnership and what it means for the future of the drug.

Other financial details shared in the announcement include the $160 million Gossamer is expected to receive as development reimbursement payment. Moreover, as part of future milestone payments, the company is entitled to $180 million in sales milestones and $146 million in regulatory milestones.

Regarding profits, losses, and regional responsibilities, within the context of the U.S., Gossamer and Chiesi will share both profits and losses equally. Not only will Gossamer be responsible for leading commercialization for the drug in the U.S., but the company will also contribute to the booking of sales for PAH and PH-ILD and towards 50% of the commercialization activities.

In comparison, Chiesi will be responsible for the commercialization in the U.S. for other indications. Since Chiesi will also have the exclusive rights to commercialize the drug outside of the U.S., it will be paying Gossamer escalating mid-to-high teens royalties on net sales outside of the US.

In the United States alone, pulmonary arterial hypertension (PAH) affects about 40,000 people. The latest drug to gain Food and Drug Administration approval for the disease is Merck’s Winrevair, which was approved by the agency in March of this year.