GSK and Bellus Health have entered into an agreement under which GSK will acquire Bellus, a Canada-based, late-stage biopharmaceutical company focused on treating refractory chronic cough (RCC) for approximately $2 billion (£1.6 billion).

According to the company, the acquisition provides GSK access to camlipixant, a potential best-in-class and highly selective P2X3 antagonist currently in phase III development for the first-line treatment of adult patients with RCC.

P2X3 is a validated biological target implicated in cough reflex hypersensitization, and camlipixant is a highly selective P2X3 antagonist. Current clinical data show that by selectively inhibiting P2X3 receptors, camlipixant may reduce cough frequency for patients suffering from RCC with a relatively low incidence of dysgeusia, the taste disturbance adverse event associated with other medicines that broadly target the P2X2/3 receptor. These taste disturbances frequently lead to patients discontinuing treatment.

“Patients suffering from severe forms of refractory chronic cough can experience over 900 coughs daily, resulting in quality-of-life issues,” said Luke Miels, chief commercial officer, GSK. “Camlipixant, a novel, highly selective P2X3 antagonist, has the potential to be a best-in-class treatment with significant sales potential. This proposed acquisition complements our portfolio of specialty medicines and builds on our expertise in respiratory therapies.”

The acquisition of Bellus is highly synergistic with GSK’s expertise in respiratory medicines and is further supported by GSK’s R&D, manufacturing, and commercialization capabilities.

Following the anticipated regulatory approval and launch of camlipixant in 2026, the acquisition is expected to be accretive to adjusted EPS from 2027 and has the potential to deliver significant sales through 2031 and beyond.

In December 2021, Bellus announced positive data from the SOOTHE phase IIb trial, indicating that it met its primary endpoint for the 50 mg and 200 mg twice-daily doses. Based on these data, Bellus initiated the CALM phase III development programme consisting of the CALM-1 and CALM-2 trials, with data anticipated in H2 2024 and 2025, respectively. BELLUS is also evaluating a QD (once-daily) formulation for camlipixant, which is currently in phase I.

Roberto Bellini, CEO of Bellus, said, “This acquisition recognizes the value of our highly selective P2X3 antagonist camlipixant and validates the hard work and dedication of all the Bellus employees in advancing camlipixant to date. As a leader in respiratory research for over five decades, GSK shares our commitment to bettering the lives of individuals suffering from a persistent cough and is the ideal Company to rapidly bring camlipixant to the millions suffering from refractory chronic cough around the world.”