Recurrent chronic cough has no FDA-approved treatments, but efforts are underway to bring one to the market. GSK sees a late-stage drug candidate from Bellus Health as potentially best in class and the pharmaceutical giant has agreed to pay $2 billion to acquire the company.

According to deal terms announced Tuesday, GSK will pay $14.75 cash for each share of Bellus, which represents a 103% premium to the biotech’s closing stock price on Monday.

Recurrent chronic cough is defined as a persistent cough that lasts for more than eight weeks and does not respond to treatment. In severe cases, an individual can experience more than 900 coughs daily. The coughing can be associated with an underlying condition but in some cases is unexplained. An estimated 10 million people worldwide suffer from recurrent chronic cough.

Laval, Quebec-based Bellus aims to treat the coughing condition with camlipixant, a small molecule that blocks P2X3, a receptor associated with the cough mechanism. The drug is designed to be selective to its target, reducing the chance of causing an unpleasant side effect that leads to a persistent foul taste in the mouth. That side effect was the most common one reported in mid-stage clinical testing of Merck’s P2X3-targeting cough drug, gefapixant. The FDA rejected that drug last year, asking for more information about the measurement of efficacy. Merck said in its annual report that it expects to resubmit its application in the first half of 2023.

Bayer was also pursuing recurrent chronic cough and its contender, eliapixant, posted positive mid-stage clinical data. But shortly after the FDA turned down Merck’s drug, Bayer abandoned development of its P2X3-targeting molecule.

In Bellus’s Phase 2b trial of camlipixant, a twice-daily pill, the company reported that the low rates of the taste side effect were reported across all of the doses tested. Two placebo-controlled Phase 3 studies are underway. A once-daily formulation of the drug is being evaluated in a Phase 1 study.

The acquisition still needs regulatory approval as well as the blessing of Bellus shareholders. The companies expect to close the transaction in the third quarter of this year. GSK estimates the Bellus drug could receive regulatory approval in 2026, followed by a launch that year.

“Camlipixant, a novel, highly selective P2X3 antagonist, has the potential to be a best-in-class treatment with significant sales potential,” GSK Chief Commercial Officer Luke Miel said in a prepared statement. “This proposed acquisition complements our portfolio of specialty medicines and builds on our expertise in respiratory therapies.”

Photo by GSK