GSK halts camlipixant development in refractory chronic cough after mixed phase III results
CALM-1 hit its primary endpoint but CALM-2 did not, and GSK said the combined data will not change patient care.
GSK announced on 17 July 2026 an update on the CALM-1 and CALM-2 phase III trials of camlipixant, a P2X3 receptor antagonist tested in adults with refractory chronic cough (RCC), a condition the company described as complex and under-recognized with limited treatment options.1
The two studies produced different results. In CALM-1, the 50mg twice-daily dose of camlipixant achieved a statistically significant drop in 24-hour cough frequency compared with placebo at week 12, meeting the trial's primary goal.1 The same dose and endpoint did not reach statistical significance in CALM-2 at week 24.1 A lower 25mg twice-daily dose failed to reach significance in either trial.1 Key secondary measures, including a Chronic Cough Diary score, also fell short of target thresholds in both studies.1
On safety, rates and severity of treatment-related adverse events were comparable between camlipixant and placebo groups across both trials.1
Weighing the full dataset, GSK said the efficacy shown was too limited to change how RCC patients are treated.1 As a result, the company has stopped further development of camlipixant for this indication.1 GSK plans to submit the CALM program findings for future publication or presentation to add to scientific knowledge of RCC.1
Camlipixant is not being abandoned entirely. A separate phase IIb study, called BALANCE (NCT07519395), is still ongoing, testing the drug's efficacy and safety in adults with diarrhea-predominant and mixed-type irritable bowel syndrome.1
Written by readthrough’s AI from the linked primary sources and fact-checked against them automatically before publishing. Not investment advice.