A Study of Gefapixant (MK-7264) in Adult Participants With Chronic Cough (MK-7264-030)-China Extension
Condition: Chronic Cough
MeSH terms: Cough
Intervention: Gefapixant 45 mg twice daily (BID); Gefapixant 15 mg BID; Placebo; Gefapixant 45 mg BID
Intervention description: Gefapixant 45 mg tablet to be administered orally BID; Gefapixant 15 mg tablet to be administered orally BID; Placebo tablet administered orally BID; Gefapixant 45 mg tablet to be administered orally BID
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants with refractory or unexplained chronic cough will be randomized to 1 of 3 treatment groups: gefapixant 45 mg twice daily (BID), gefapixant 15 mg BID, or placebo.
Masking: Double (Participant, Investigator)
Enrollment: 161.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No

Summary:

      The primary objective of this study will be to evaluate the efficacy of gefapixant (MK-7264)
      in reducing cough frequency as measured over a 24-hour period. It is hypothesized that at
      least one dose of gefapixant is superior to placebo in reducing coughs per hour (over 24
      hours) at Week 24.
    

Eligibility criteria:

        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 or is currently participating in or has
             participated in an interventional clinical study