A Study of Gefapixant (MK-7264) in Adult Participants With Chronic Cough (MK-7264-030)

Merck Sharp & Dohme LLC1,317 enrolled

Overview

The primary objectives of this study are to evaluate the efficacy of gefapixant (MK-7264) in reducing cough frequency as measured over a 24-hour period, and to determine the safety and tolerability of gefapixant. The primary hypothesis is that at least one dose of gefapixant is superior to placebo in reducing coughs per hour (over 24 hours) at Week 24.

This study will have a main 24-week treatment period and a 28-week extension period of treatment (total treatment period of 52 weeks). Participants at selected sites and countries who complete the main and extension study periods may consent to participate in an observational, 12-week, Off-treatment Durability Study Period. Any assessments conducted in the observational period will be exploratory.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

1,317

Conditions

Chronic Cough

Interventions

PlaceboDRUG

Placebo tablet administered orally BID

Gefapixant 15 mg BIDDRUG

Gefapixant 15 mg tablet administered orally BID

Gefapixant 45 mg BIDDRUG

Gefapixant 45 mg tablet administered orally BID

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * 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) Exclusion Criteria: * Is a current smoker or has given up smoking within 12 months of Screening, or is a former smoker with greater than 20 pack-years * Has a history of respiratory tract infection or recent clinically significant change in pulmonary status * Has a history of chronic bronchitis * Is currently taking an angiotensin converting enzyme inhibitor (ACEI), or has used an ACEI within 3 months of Screening * Has an estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m\^2 at Screening OR an eGFR ≥30 mL/min/1.73 m\^2 and \<50 mL/min/1.73 m\^2 at Screening with unstable renal function * Has a history of malignancy ≤5 years * Is a user of recreational or illicit drugs or has had a recent history of drug or alcohol abuse or dependence * Has a history of anaphylaxis or cutaneous adverse drug reaction (with or without systemic symptoms) to sulfonamide antibiotics or other sulfonamide-containing drugs * Has a known allergy/sensitivity or contraindication to gefapixant * Has donated or lost ≥1 unit of blood within 8 weeks prior to the first dose of gefapixant * Has previously received gefapixant * Currently participating in or has participated in an interventional clinical study within 30 days of screening

Locations (171)

Outcomes

Primary Outcomes

Model-Based Geometric Mean Ratio (GMR) of 24-Hour Coughs Per Hour at Week 24/Baseline

24-hour coughs per hour was defined as the average hourly cough frequency based on 24-hour sound recordings using a digital recording device (cough monitor). A longitudinal analysis of covariance (ANCOVA) model was applied to log-transformed cough data to determine geometric mean (GM) 24-hour coughs per hour at baseline and week 24. The GMR (Week 24 GM 24-hour coughs per hour divided by Baseline GM 24-hour coughs per hour) is reported.

Time frame: Baseline, Week 24

Number of Participants Who Experienced At Least One Adverse Event (AE) During Treatment and Follow-up

An AE is 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. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.

Time frame: Up to 54 Weeks

Number of Participants Who Discontinued a Study Drug Due to an AE

Time frame: Up to 52 weeks

Secondary Outcomes

Model-Based GMR of Awake Coughs Per Hour at Week 24/Baseline

Awake coughs per hour was defined as the average hourly cough frequency while the participant is awake, based on a 24-hour interval of sound recordings using a digital recording device (cough monitor). ANCOVA model was applied to log-transformed cough data to determine GM of awake coughs per hour at baseline and week 24. The GMR (Week 24 GM awake coughs per hour divided by Baseline GM awake coughs per hour) is reported.

Data from ClinicalTrials.gov

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Phoenix Medical Group ( Site 0022)

Peoria, Arizona, United States

Pulmonary Associates, PA ( Site 0063)

Phoenix, Arizona, United States

Clinical Research Consortium ( Site 0088)

Tempe, Arizona, United States

Allergy & Asthma Associates of SCV Research Center ( Site 0064)

San Jose, California, United States

Lenus Research & Medical Group Llc ( Site 0075)

Sweetwater, Florida, United States

Atlanta Allergy & Asthma Clinic PA ( Site 0029)

Stockbridge, Georgia, United States

Rush University Medical Center ( Site 0103)

Chicago, Illinois, United States

Healthcare Research Network LLC ( Site 0093)

Flossmoor, Illinois, United States

Abraham Research, PLLC ( Site 0107)

Fort Mitchell, Kentucky, United States

Paul A. Shapero, MD ( Site 0104)

Bangor, Maine, United States

...and 161 more locations

Time frame: Baseline, Week 24

Percentage of Participants With a ≥1.3 Point Change From Baseline in the Leicester Questionnaire (LCQ) Total Score at Week 24

The 19-item LCQ assessed the impact of chronic cough in three health-related quality of life (HRQoL) domains (physical, social and psychological). The LCQ is calculated as a mean score for each domain ranging from 1 to 7, with a total score ranging from 3 to 21. Higher scores indicate better HRQoL. A clinically meaningful improvement from baseline in HRQoL was defined as ≥1.3-point increase in the LCQ total score at Week 24. The percentage of participants (logistic regression model-based) with a ≥1.3-point increase in the LCQ total score at Week 24 is presented.

Time frame: Baseline, Week 24

Percentage of Participants With a ≤-30% Change From Baseline in 24-hour Coughs Per Hour at Week 24

24-hour coughs per hour was defined as the average hourly cough frequency based on 24-hour sound recordings using a digital recording device (cough monitor). A clinically meaningful improvement from baseline is defined as a ≤-30% change (≥30% reduction) in 24-hour coughs per hour at week 24. The percentage of participants (logistic regression model-based) with a ≤ -30% change from baseline in 24-hour coughs per hour at Week 24 (≥30% reduction from baseline) is presented.

Time frame: Baseline, Week 24

Percentage of Participants With ≤-1.3 Point Change From Baseline of Mean Weekly Cough Severity Diary (CSD) Total Score at Week 24

The 7-item CSD was used to record participants' daily cough frequency, cough intensity, and disruption due to cough. Each item was rated on an 11-point scale ranging from 0 (best) to 10 (worst); the total daily CSD score was the sum of these seven item scores (Min=0, Max=70). Mean weekly CSD total score was defined as the average of the mean total daily scores collected during the week prior to each visit. The percentage of participants (logistic regression model-based) with a ≤-1.3 point change from baseline in CSD at Week 24 (or ≥1.3 point reduction from baseline) is reported.

Time frame: Baseline, Week 24

Percentage of Participants With ≤-2.7 Point Change From Baseline of Mean Weekly CSD Total Score at Week 24

The 7-item CSD was used to record participants' daily cough frequency, cough intensity, and disruption due to cough. Each item was rated on an 11-point scale ranging from 0 (best) to 10 (worst); the total daily CSD score was the sum of these seven item scores (Min=0, Max=70). Mean weekly CSD total score was defined as the average of the mean total daily scores collected during the week prior to each visit. The percentage of participants (logistic regression model-based) with a ≤-2.7 point change from baseline in CSD at Week 24 (or ≥2.7 point reduction from baseline) is reported.

Time frame: Baseline, Week 24

Percentage of Participants With a ≤-30 Millimeter (mm) Change From Baseline in Cough Severity Visual Analog Scale (VAS) Score at Week 24

The VAS is a single-item questionnaire with the response on a 100- point scale ranging from 0 ("No Cough") to 100 ("Extremely Severe Cough"). Mean weekly VAS score was defined as the average of the VAS scores collected during the week prior to each visit. The percentage of participants (logistic regression model-based) with a ≤-30 mm change from baseline in cough severity VAS score at Week 24 is reported.

Time frame: Baseline, Week 24