Gefapixant effective option for uncontrolled chronic cough, finds study

New Orleans: Gefapixant is an orally administered, selective P2X3 receptor antagonist. It is believed that excessive activation of P2X3 receptors is associated with neuronal hypersensitization in the airways and lungs leading to chronic cough.

Chronic refractory cough (CRC) is defined as a cough that persists despite guideline-based treatment. It is seen in 20-46% of patients presenting to specialist cough clinics and it has a substantial impact on the quality of life and healthcare utilization.

2 ongoing pivotal phase 3 trials (COUGH-1 and COUGH-2) for gefapixant (MK-7264) for the treatment of refractory or unexplained chronic cough is conducted which is published in the journal Clinical Trials.

The study is a randomized, double-blind, placebo-controlled that enrolled 732 and 1317 adult patients with refractory or unexplained chronic cough for at least 1 year, respectively. Both studies randomized patients to 1 of 3 cohorts: gefapixant 45mg or 15mg twice daily, or placebo. 

Inclusion Criteria were:

• Chest radiograph or computed tomography scan of the thorax (within 5 years of Screening/Visit 1 and after the onset of chronic cough) not demonstrating any abnormality considered to be significantly contributing to the chronic cough or any other clinically significant lung disease in the opinion of the principal investigator or the sub-investigator

• Has had chronic cough for at least 1 year with a diagnosis of refractory chronic cough or unexplained chronic cough

• Is a female who is not pregnant, not breastfeeding, not of childbearing potential, or agrees to follow contraceptive guidance

• Provides written informed consent and is willing and able to comply with the study protocol (including use of the digital cough recording device and completion of study questionnaires)

The primary endpoint was 12-week Awake Objective Cough Frequency, with secondary endpoints including various measures of cough severity and quality of life: the 7-item Cough Severity Diary (CSD), the participant-rated Patient Global Impression of Change (PGIC), and the 19-item Leicester Cough Questionnaire (LCQ).

Improvements in [patient reported outcomes] in this trial are consistent with data on objective cough frequency reductions and indicate benefits related to the quality of life," the researchers concluded.

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Clinical Trials