Efficacy of Gefapixant, a P2X₃ Antagonist, for Refractory Atopic Cough

Abstract

Cough, a frequent symptom encountered in clinical practice, often has a considerable impact on patients’ lives. There is an urgent need to investigate more potent antitussive treatments for chronic refractory cough, particularly atopic cough, which is a major cause of chronic refractory cough in Japan. Previous studies have shown that eosinophilic tracheobronchitis with hypersensitivity to sensory nerve C-fibers is the pathophysiology of atopic cough. Gefapixant is a first-in-class P2X₃ antagonist that has recently become available for clinical use in patients with refractory coughs. A 64-year-old female non-smoker presented to our hospital with a complaint of chronic intractable cough due to atopic cough. Addition of gefapixant (90 mg/day) to her previous treatment improved her distressing cough, despite the partial efficacy of many other drugs. The findings of this case demonstrate that P2X₃ inhibition is a viable therapeutic option for patients with chronic refractory cough caused by atopic cough. This case report offers valuable information regarding currently available treatment options for refractory chronic refractory cough caused by atopic cough. There remains an urgent need to clarify the disease entities presenting with chronic cough that can be effectively treated by inhibiting P2X₃.

Plain Language Summary

There is an urgent need to investigate more potent antitussive treatments for chronic refractory cough, because cough has a considerable impact on patients’ lives. Previous studies have shown that eosinophilic tracheobronchitis with hypersensitivity of sensory nerve C-fibers is the pathophysiology of atopic cough, which is a major cause of chronic cough in Japan. Gefapixant is a first-in-class P2X₃ antagonist that has recently become available for clinical use in patients with refractory coughs. Herein, we present the case of a 64-year-old female with a refractory atopic cough. The gefapixant add-on improved her distressing cough, indicating that P2X₃ inhibition could be a viable therapeutic option for patients with chronic refractory cough caused by atopic cough.

Keywords:

• chronic cough
• atopic cough
• gefapixant
• P2X₃

Abbreviations

BAL, bronchoalveolar lavage eosinophilia; BHR, bronchial hyperresponsiveness; NAEB, nonasthmatic eosinophilic ERS, European Respiratory Society; FeNO, fractional exhaled nitric oxide; FEV1, forced expiratory volume in one second; FVC, forced vital capacity; LCQ, Leicester Cough Questionnaire; VAS, visual analog scale.

Ethical Approval

Institutional approval is not required for publication, so written informed consent was obtained from the patient regarding the publication of details.

Acknowledgment

The authors thank Alison Sherwin, PhD, and Edanz (https://jp.edanz.com/ac) for editing the draft of this manuscript.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

All authors declare that they have no conflicts of interest.

Additional information

Funding

This study was supported by a grant form “Private University Research Branding Project on intractable immune and allergic diseases” from Kansai Medical University.