The P2X3 receptor antagonist filapixant in patients with refractory chronic cough: a randomized controlled trial

Christian Friedrich*, Klaus Francke, Surinder S Birring, Jan Willem K van den Berg, Paul A Marsden, Lorcan McGarvey, Alice M Turner, Pascal Wielders, Isabella Gashaw, Stefan Klein, Alyn H Morice

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)
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P2X3 receptor antagonists seem to have a promising potential for treating patients with refractory chronic cough. In this double-blind, randomized, placebo-controlled study, we investigated the efficacy, safety, and tolerability of the novel selective P2X3 receptor antagonist filapixant (BAY1902607) in patients with refractory chronic cough. Following a crossover design, 23 patients with refractory chronic cough (age: 60.4 ± 9.1 years) received ascending doses of filapixant in one period (20, 80, 150, and 250 mg, twice daily, 4-days-on/3-days-off) and placebo in the other. The primary efficacy endpoint was the 24-h cough frequency on Day 4 of each dosing step. Further, subjective cough severity and health-related quality of life were assessed. Filapixant at doses ≥ 80 mg significantly reduced cough frequency and severity and improved cough health-related quality of life. Reductions in 24-h cough frequency over placebo ranged from 17% (80 mg dose) to 37% (250 mg dose), reductions over baseline from 23% (80 mg) to 41% (250 mg) (placebo: 6%). Reductions in cough severity ratings on a 100-mm visual analog scale ranged from 8 mm (80 mg) to 21 mm (250 mg). No serious or severe adverse events or adverse events leading to discontinuation of treatment were reported. Taste-related adverse events occurred in 4%, 13%, 43%, and 57% of patients treated with filapixant 20, 80, 150, and 250 mg, respectively, and in 12% treated with placebo. Filapixant proved to be efficacious, safe, and-apart from the occurrence of taste disturbances, especially at higher dosages-well tolerated during the short therapeutic intervention.
Original languageEnglish
Article number109
JournalRespiratory Research
Early online date11 Apr 2023
Publication statusEarly online date - 11 Apr 2023


  • Chronic Disease
  • Aged
  • P2X3 receptor antagonist
  • Taste disturbances
  • Purinergic P2X Receptor Antagonists
  • Humans
  • Cough reflex sensitivity
  • Receptor pharmacology
  • Middle Aged
  • Proof of concept
  • Airway hyperreactivity
  • Quality of Life
  • Cough - chemically induced
  • Airway hyperresponsiveness
  • Double-Blind Method
  • Refractory chronic cough


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