GSK has decided to discontinue the development of camlipixant, its experimental drug for refractory chronic cough (RCC), following disappointing results from late-stage clinical trials. While a 50 mg dose showed a reduction in 24-hour cough frequency at 12 weeks compared to a placebo, it failed to maintain statistical significance at 24 weeks. The lower 25 mg dose, along with both dosages for secondary endpoints, also did not achieve statistical significance in either study. GSK stated that, based on the aggregate data, the demonstrated efficacy was unlikely to significantly improve patient care, even though chronic cough affects millions globally and can lead to severe issues like sleep loss, depression, and social isolation. The drug was initially seen as a potential breakthrough, especially after the U.S. FDA rejected competitor MSD’s gefapixant for the same condition, leaving an open market for GSK.
This decision is a significant setback for GSK's new CEO, Luke Miels, who is focused on accelerating the development of new medicines and acquiring new assets to bolster the company's late-stage pipeline. Miels aims to increase revenues from £31 billion in 2024 to £40 billion by 2031, and this failure adds pressure ahead of anticipated patent expirations starting in 2028. Analysts have a "Moderate Buy" consensus on GSK stock, with an average price target of $68.55, suggesting a 29.90% upside before this news. The company had acquired Canada-based Bellus Health for $2 billion in April 2023, primarily for camlipixant, which was then in Phase III development and expected to launch in 2026.
Despite the discontinuation for chronic cough, GSK plans to continue evaluating camlipixant as a potential treatment for irritable bowel syndrome. Refractory chronic cough is defined as a cough lasting more than eight weeks, often persisting despite treatment for underlying conditions, or having no clear cause, with some sufferers experiencing over 900 coughs daily. The failure of camlipixant highlights the challenges in developing effective treatments for this condition, particularly as there are currently no FDA-approved therapies for chronic cough. Both camlipixant and gefapixant are P2X3 antagonists, a class of drugs believed to target receptors responsible for chronic cough.
