Efficacy and Safety of Gefapixant (MK-7264) in Adult Participants With Recent Onset Chronic Cough (MK-7264-043)

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the efficacy and safety of gefapixant in participants with recent onset chronic cough (duration >8 weeks after onset of cough symptoms) for <12 months and a diagnosis of refractory or unexplained chronic cough. The primary hypothesis is that gefapixant is superior to placebo in improving cough-related quality of life measured as change from baseline in the Leicester Cough Questionnaire (LCQ) total score at Week 12.

Official Title
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A Phase 3b Randomized, Double-blind, Placebo Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Gefapixant in Adult Participants With Recent Onset Chronic Cough

Conditions
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Chronic Cough

Intervention / Treatment
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* Drug: Gefapixant
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chest radiograph or CT thorax (within 1 year 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 subinvestigator Has chronic cough (defined as duration of >8 weeks after onset of cough symptoms) for <12 months prior to the screening visit (<14 months after onset of cough symptoms) Has a diagnosis of refractory chronic cough or unexplained chronic cough Female participants are not pregnant, not breastfeeding, not of childbearing potential, or agree to follow contraceptive guidance Exclusion Criteria: Is a current smoker Has given up smoking within 12 months of screening Is a former smoker with a smoking history greater than 20 pack-years (1 pack of 20 cigarettes per day for 20 years) Has a history of respiratory tract infection or recent change in pulmonary status within 4 weeks of screening Has a history of chronic bronchitis, defined as cough that produces >1 tablespoon of phlegm, that occurs every day for at least 3 months in a row Has a history of malignancy ≤5 years prior to signing informed consent except for adequately treated basal cell or squamous cell skin cancer or cervical cancer Is a user of recreational or illicit drugs or a recent history (within the last year) of drug or alcohol abuse Has a history of anaphylaxis or cutaneous adverse drug reaction to sulfonamide-containing drugs Has a known allergy to gefapixant or its excipients Has donated or lost ≥1 unit ( 300 mL) of blood within 8 weeks prior to first dose of gefapixant Has previously received gefapixant Is currently participating or has participated in an interventional clinical study within 30 days of participating in this current study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Gefapixant<br>Participants will receive gefapixant at a dose of 45 mg administered as an oral tablet twice daily for 12 weeks. | Drug: Gefapixant<br>* Administered twice daily as an oral tablet of 45 mg<br>* Other names: MK-7264;|
| Placebo Comparator: Placebo<br>Participants will receive placebo matching gefapixant, administered as an oral tablet twice daily for 12 weeks. | Drug: Placebo<br>* Administered twice daily as a placebo oral tablet matching gefapixant<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in the Leicester Cough Questionnaire (LCQ) Total Score at Week 12 | Participants will be asked to complete the LCQ to assess the impact of their cough severity on health related quality of life (HRQoL) over the past 2 weeks. The LCQ is a 19-item, cough-specific HRQoL questionnaire. Each item on the LCQ assesses symptoms using a 7-point scale ranging from 1 to 7. The LCQ contains three domains on physical, psychological, and social functioning, and each domain score is calculated as the mean score of the items (range: 1 to 7) within the domain. The LCQ total score is the sum of the 3 domains, with a range from 3 (lowest total score) to 21 (highest total score). Higher scores indicate better HRQoL. The change from baseline in LCQ total score is calculated. | Baseline, Week 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in the Cough Severity Visual Analog Scale (VAS) Score at Week 12 | Participants will be asked to complete the VAS questionnaire to assess the severity of their cough over the past 24-hours. The Cough Severity VAS is a single-item questionnaire asking the participant to rate the severity of their cough on a 100-point scale ranging from 0 (No Cough) to 100 (Extremely Severe Cough). Higher scores indicate greater severity of cough. The change from baseline in VAS score is calculated. | Baseline, Week 12 | 
| Percentage of Participants With One or More Adverse Events (AEs) | An AE is defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The percentage of participants with one or more AEs is presented. | Up to approximately 14 weeks | 
| Percentage of Participants Who Discontinue Study Drug Due to an AE | An AE is defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The percentage of participants who discontinue study drug due to an AE is presented. | Up to approximately 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cough, Respiration disorders, Respiratory tract diseases, Signs and symptoms, respiratory, Signs and symptoms