Gossamer Bio and Chiesi Announce $3.5 Billion Global Collaboration to Develop and Commercialize Seralutinib for Pulmonary Arterial Hypertension

Recently, Gossamer Bio (“Gossamer”) and Chiesi Farmaceutici (“Chiesi”) announced that they have entered into a global collaboration and license agreement to jointly develop and commercialize Seralutinib for the treatment of pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH-ILD).

According to the terms of the agreement,Gossamer Bio will receive a $160 million development compensation payment from Chiesi Farmaceutici, and has the opportunity to earn up to $146 million in regulatory milestone payments and $180 million in commercialization milestone payments.. Gossamer will continue to lead the global development of seralutinib in PAH and PH-ILD, with both parties sharing development costs equally. Gossamer will be responsible for the commercialization of seralutinib for PAH and PH-ILD in the United States, while Chiesi will handle the commercialization of the drug for other indications in the United States and will hold exclusive rights to commercialize seralutinib outside the United States.

Gossamer Bio is a clinical-stage biopharmaceutical company dedicated to developing innovative immunology-based therapies, with a primary focus on autoimmune diseases, inflammation, and tumor immunology. The company was co-founded by Dr. Faheem Hasnain, former CEO of Receptos (acquired by Celgene in 2015), and Dr. Sheila Gujrathi, its former Chief Medical Officer.

In January 2018, Gossamer Bio made its debut in the capital markets,In just six months, the company raised a cumulative total of $330 million in financing, with investors including Hillhouse Capital, Arch Venture Partners, Omega Funds, Invus, and Baupost Group.One year later, Gossamer Bio officially listed on the NASDAQ, raising approximately $276 million.。

At this time, Gossamer Bio’s drug development pipeline includes four candidate drugs in clinical and preclinical stages, among which is the key candidate Seralutinib, being developed in collaboration with Chiesi.

Seralutinib is a tyrosine kinase inhibitor for the treatment of PAH, targeting PDGFRα/β, CSF1R, and c-KIT, thereby blocking the inflammation, proliferation, and fibrosis that drive PAH.Seralutinib is formulated as a dry powder for inhalation and can be administered via a dry powder inhaler.

Previously, Gossamer Bio published the results of the Phase 2 clinical trial (TORREY) of Seralutinib in The Lancet Respiratory Medicine. TORREY was a Phase 2, randomized, multicenter, multinational, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of Seralutinib in patients with pulmonary arterial hypertension (PAH). In this trial, 86 patients were randomized to receive either Seralutinib or placebo via dry powder inhalation twice daily for 24 weeks. The study results showed that, compared with the placebo group,The seralutinib group demonstrated statistically significant improvements in the primary endpoint, reduction in pulmonary vascular resistance (PVR), and other key disease metrics, including indices of right heart structure and function.¹。

In May 2023, Gossamer Bio initiated the Phase 3 clinical trial of Seralutinib (PROSERA) to evaluate its efficacy and safety in adult patients with pulmonary arterial hypertension (PAH) receiving background therapy for World Health Organization (WHO) Functional Class (FC) II or III. Notably,Gossamer Bio and Chiesi Farmaceutici are expected to initiate a global Phase 3 registrational clinical trial in mid-2025 for PH-ILD, to evaluate the efficacy of seralutinib in other indications with high unmet medical needs.。

Gossamer Bio’s journey from its founding to its IPO was marked by continuous highlights, drawing significant attention from capital markets and investors. However, the good times did not last; starting in 2020, Gossamer Bio encountered multiple developmental challenges.

First, clinical trials for the drugs in its R&D pipeline have encountered successive setbacks.. In October 2020, Gossamer Bio announced the top-line data from its Phase 2 clinical trial of GB001, a DP2 inhibitor candidate drug, for the treatment of asthma and chronic rhinosinusitis. Among them,The LEDA Phase 2b clinical trial for moderate-to-severe eosinophilic asthma failed to meet its primary endpoint, and the TITAN Phase 2a clinical trial for chronic rhinosinusitis failed to meet both its primary and secondary endpoints.As a result, Gossamer Bio's stock price fell by 39.51%.

March 2023,Gossamer Bio Announces Discontinuation of BTK Inhibitor GB5121 Development, as two patient deaths occurred in a Phase 1/2 clinical trial, the FDA has suspended all clinical trials of GB5121.

Secondly,Seralutinib Phase 2 Clinical Trial Succeeds, Yet Stock Price Plunges 74%In December 2022, Gossamer Bio announced that the Phase 2 TORREY study of seralutinib for the treatment of patients with pulmonary arterial hypertension (PAH) had met its primary endpoint. However, Joseph Schwartz, an analyst at SVB Securities, stated that the therapy’s efficacy was not superior to Merck’s sotatercept, as both of its endpoints were lower than the placebo-adjusted data from the Phase 2 clinical trial of sotatercept.Gossamer Bio failed to meet investor expectations, causing its stock price to plummet again and remain sluggish in its recovery.。

Following a series of setbacks, Gossamer Bio announced in its first-quarter 2023 financial report that it would implement a workforce reduction and restructuring plan.Apart from Seralutinib, Gossamer Bio has discontinued all other clinical and preclinical programs and announced a workforce reduction of more than 25%.。

Nowadays, Gossamer Bio, once “all the rage,” has lost its former luster. Although the company held nearly $300 million in cash, cash equivalents, and marketable securities as of the end of 2023, its market capitalization has plummeted to below $170 million over the past year and a half. Under these circumstances, the transaction with Chiesi Farmaceutici will alleviate investors’ concerns about Gossamer Bio’s future development, thereby further ensuring the smooth progress of subsequent clinical trials for seralutinib.

However, in the PAH drug market, Gossamer faces numerous formidable competitors. In March this year,Merck’s First-in-Class Drug Winrevair (sotatercept-csrk) Approved by FDA for the Treatment of Adult Patients with PAH. Daina Graybosch of Leerink Partners expects Winrevair’s sales to reach $1.9 billion by 2025. In addition, just days before Winrevair’s approval,The FDA has also approved Johnson & Johnson’s Opsynvi single-tablet combination therapy for marketing. Opsynvi becomes the first PAH single-tablet combination therapy approved by the FDA.。

Nevertheless, Gossamer remains confident in Seralutinib. To further ensure the smooth development of Seralutinib, Gossamer has also hired Bob Smith, former Senior Vice President at Merck, to lead commercialization efforts. Bob Smith previously led the launches of two blockbuster PAH drugs—Opsumit and Uptravi—and was responsible for the pre-approval commercialization strategy for Winrevair.

Will Gossamer Bio secure a place in the PAH drug market in the future? Time will tell!

References:

1. https://doi.org/10.1016/S2213-2600(24)00072-9