An 8-Week Refractory Chronic Cough Study (MK-7264-021)

Study Overview
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Brief Summary
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This was an 8-week randomized, parallel, double-blind, placebo-controlled study of gefapixant (AF-219) in participants with refractory chronic cough.

Official Title
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A Randomized, Parallel, Double-Blind Study to Assess the Efficacy and Tolerability of AF-219 in Subjects With Refractory Chronic Cough

Conditions
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Refractory Chronic Cough

Intervention / Treatment
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* Drug: Gefapixant
* Drug: Placebo (for gefapixant)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Women and Men between 18 and 80 years of age inclusive Have refractory chronic cough Women of child-bearing potential must use 2 forms of acceptable birth control Have provided written informed consent. Are willing and able to comply with all aspects of the protocol. Exclusion Criteria: Current smoker Forced Expiratory Volume (FEV1)/Forced Vital Capacity (FVC) < 60% History of upper respiratory tract infection or recent significant change in pulmonary status within 4 weeks of the Baseline History of opioid use within 1 week of the Baseline Visit Body mass index (BMI) <18 kg/m2 or ≥ 40 kg/m2 History of concurrent malignancy or recurrence of malignancy within 2 years prior to Screening (not including participants with <3 excised basal cell carcinomas) Screening systolic blood pressure (SBP) >160 mm Hg or a diastolic blood pressure (DBP) >90 mm Hg Significantly abnormal laboratory tests at Screening Clinically significant abnormal electrocardiogram (ECG) Pregnant or Breastfeeding Other severe, acute, or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with trial participation or investigational product administration or may interfere with the interpretation of trial results and, in the judgment of the Investigator or Sponsor, would make the participants inappropriate for entry into this trial

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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 15 mg twice daily<br>Two 7.5 mg gefapixant tablets administered by mouth twice daily for 8 weeks | Drug: Gefapixant<br>* Gefapixant tablets administered by mouth twice daily for 8 weeks<br>* Other names: MK-7264;|
| Experimental: Gefapixant 30 mg twice daily<br>Four 7.5 mg gefapixant tablets administered by mouth twice daily for 8 weeks | Drug: Gefapixant<br>* Gefapixant tablets administered by mouth twice daily for 8 weeks<br>* Other names: MK-7264;|
| Experimental: Gefapixant 50 mg twice daily<br>One 50 mg gefapixant tablet administered by mouth twice daily for 8 weeks | Drug: Gefapixant<br>* Gefapixant tablets administered by mouth twice daily for 8 weeks<br>* Other names: MK-7264;|
| Experimental: Placebo to match gefapixant<br>Matching placebo tablets administered by mouth twice daily for 8 weeks | Drug: Placebo (for gefapixant)<br>* Matching placebo to gefapixant tablets administered by mouth twice daily for 8 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Awake Cough Frequency After 8 Weeks of Treatment. | Cough monitoring was conducted for 24 hours while awake, at pre-dose on Day 0, and after administration of the study drug on Day 56. The cough frequency is the coughs/hr over each 24 hour period. An independent cough monitoring core lab provided documentation of the time of each cough event over each 24-hour period. A negative change indicates a decrease in cough frequency, while a positive change indicates an increase in cough frequency. | Baseline and Week 8 (Day 56) |