Researchers conducted a randomized controlled trial to see if mepolizumab helps people with chronic cough caused by eosinophilic airways disease. The study included 30 patients who had coughing that did not respond to standard treatments and showed high levels of eosinophils in their sputum. Participants received either mepolizumab injections every four weeks or a placebo for 12 weeks.
The results showed a clear difference in inflammation markers. Patients taking mepolizumab had significantly lower levels of eosinophils in their blood and sputum compared to those on the placebo. However, the drug did not make the coughing better. There was no improvement in how often patients coughed during the day or at night, nor was there a reduction in cough severity or improvement in quality of life scores.
Safety was not a major concern, as no major adverse events were reported during the trial. The main reason to be cautious is that this was a small study done at a single center. It is possible that reducing eosinophils is not the only way to stop coughing, or that other mechanisms drive the symptoms in these patients. Readers should not assume this drug will help their cough based on this evidence alone.