Chiesi Signs $486M Deal with Gossamer Bio for Blood Pressure Treatment

Italian pharmaceutical company Chiesi Group recently publicized a significant partnership with Gossamer Bio, centered around the development and commercialization of seralutinib, a promising treatment for pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH-ILD). The collaboration could amount to $486 million, encompassing development, regulatory milestones, and potential sales achievements.

Per the agreement, Gossamer is tasked with overseeing the global development of seralutinib specifically for PAH and PH-ILD. Seralutinib functions as a PDGFRα/β, CSF1R, and c-KIT inhibitor and is administered as a dry powder through an inhaler. Gossamer, based in San Diego, will receive $160 million to cover development costs, along with the prospect of acquiring up to $146 million from regulatory milestones and an additional $180 million tied to sales benchmarks. The company will spearhead the commercialization efforts and sales reporting for seralutinib within the U.S. for PAH and PH-ILD, with both companies contributing equally to the commercial initiatives in these indications.

Meanwhile, Chiesi will drive the U.S. commercialization of seralutinib for other indications and retain exclusive rights to the drug outside the U.S. Additionally, Chiesi will compensate Gossamer with a royalty percentage on net sales that escalates from the mid-to-high teens. Both firms will jointly cover seralutinib’s development expenses; however, Gossamer will solely finance the Phase III trial of the drug for PAH patients. The companies aim to launch a global Phase III registrational study in PH-ILD by mid-2025.

Gossamer's CEO, Faheem Hasnain, conveyed enthusiasm about the partnership, noting it allows a significant acceleration in seralutinib's development for PAH, PH-ILD, and other critical health needs. Hasnain highlighted the importance of advancing the drug into a Phase III trial for PH-ILD, emphasizing the scarcity of treatments for this condition and the potential efficacy of seralutinib in addressing it.

The Phase III trial for PAH was initiated by Gossamer last year following successful results from a Phase II study in 2022, which achieved its primary endpoint—reducing pulmonary vascular resistance, a principal factor in pulmonary hypertension. However, the study did not meet its secondary endpoint, the six-minute walk distance, falling short of statistical significance for both measures. This six-minute walk distance remains a key focus in the ongoing Phase III investigation.

Despite these mixed outcomes, both Chiesi and Gossamer maintain a positive outlook on seralutinib’s potential benefits for patients, with both companies expressing optimism about the future development and impact of the drug. Chiesi Group's CEO, Giuseppe Accogli, echoed this sentiment, describing seralutinib as a potentially revolutionary therapy for PAH and PH-ILD and expressing excitement about the global partnership with Gossamer to bring this therapy to patients.

This collaboration comes in the wake of Merck receiving FDA approval for Winrevair, the first activin signaling inhibitor for PAH, in March 2024. Notably, Merck acquired Winrevair through its $11.5 billion purchase of Acceleron Pharma in 2021, underscoring the competitive and rapidly evolving landscape of treatments for pulmonary hypertension.