A Phase 2 interventional study of Gefapixant 45 mg and Placebo in Chronic Cough, sponsored by Merck Sharp & Dohme LLC. Completed at 16 sites in Japan. Open to participants aged 20 Years and older. Per ClinicalTrials.gov, last updated 2019-10-17.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 2, Interventional, and Treatment
Among 15 studies testing gefapixant in Chronic Cough — 2 open to participants now, 2 under way, none of them phase 3. Gefapixant · Chronic Cough.
Among the 15 studies testing gefapixant in Chronic Cough, this one is the 15th largest by enrollment, is one of 4 that started in 2018, is one of 7 in phase 2, and was the 9th registered.
142 studies on the registry are indexed under Chronic Cough; 39 are open to participants now.
Browse Chronic Cough studies →2 of the 15 studies testing gefapixant in Chronic Cough are open now, in 2 countries. Recruiting first, the newest first:
Nagoya City University · Sites in Japan
Stuart Mazzone · Sites in Australia
By country, each count listing its studies:
Gefapixant: first EMA approval 2023. What it is approved for, and how studies give it, is on its page →
Of the 30 Chronic Cough studies recruiting now, 10 (33%) set no upper age limit and 11 (37%) stop at 75 or younger; 3 take children under 18; 5 take healthy volunteers.
This study: 20 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
15 studies; the count open now beside each. This study's row is marked.
First in 2011; this study’s year is marked. 4 started in 2018.
This study's enrollment of 23 is below the median of 60 across 104 interventional studies indexed under Chronic Cough.
Median enrollment 63 across the 15 interventional studies. Of the 13 that completed or were terminated, 13 (100%) have results posted.
This tab as a report to print or save as PDF → With an account.
13 of 15 have an industry lead sponsor. The 4 most frequent:
Merck Sharp & Dohme LLC is the lead sponsor of 2,166 studies on the registry; 132 are open to participants now.
Of its 501 completed or terminated interventional studies of FDA-regulated products, 370 (74%) have results posted.
Merck Sharp & Dohme LLC has 7 studies filed under Chronic Cough — fewer than ten, so there is no comparison to draw.
None of the studies under way reaches primary completion within a year.
Among the 15 studies testing gefapixant in Chronic Cough, from their registry updates:
Nothing recorded among them since 2026-09-25.
This tab as a report to print or save as PDF → With an account.
This estimation study (no hypotheses) will evaluate the safety, tolerability, and efficacy of gefapixant (MK-7264) in Japanese adult participants with unexplained or refractory chronic cough.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive a gefapixant 45 mg film-coated tablet BID for 28 days.
Drug: Gefapixant 45 mg
Participants will receive a film-coated placebo tablet matching gefapixant BID for 28 days.
Drug: Placebo
Gefapixant 45 mg (film-coated tablet) to be administered orally BID
Also known as: MK-7264
Placebo (film-coated tablet) matching gefapixant to be administered orally BID
Number of Participants Who Experienced an Adverse Event
An adverse event is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment.
Time frame: Up to 6 weeks
Number of Participants Who Discontinued Study Treatment Due to an Adverse Event
An adverse event is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment.
Time frame: Up to 4 weeks
Change From Baseline at Week 4 in Log-transformed 24-hour Coughs Per Hour
Cough frequency will be evaluated using a digital recording device which records sounds from the lungs and trachea through a chest contact sensor, as well as ambient sounds through a lapel microphone. Change from baseline in log-transformed 24-hour coughs per hour = log (24-hour coughs per hour at post-baseline) - log (24-hour coughs per hour at baseline). The denominators may be different if the recording period is actually \<24 hours but ≥20 hours).
Time frame: Baseline and Week 4
Change From Baseline at Week 4 in Log-transformed Awake Coughs Per Hour
Change from baseline at Week 4 in awake coughs per hour is the average hourly cough frequency (based on sound recordings) during the 24-hour monitoring period while the participant is awake. Change from baseline in log-transformed awake coughs per hour = log (awake coughs per hour at post-baseline) - log (awake coughs per hour at baseline) for the monitoring period the participant is awake.
Time frame: Baseline and Week 4
| Milestone | Gefapixant 45 mg | Placebo |
|---|---|---|
| Started | 11 | 12 |
| Completed | 11 | 12 |
| Not completed | 0 | 0 |
An adverse event is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment.
| Participants | Gefapixant 45 mg | Placebo |
|---|---|---|
| Number of Participants Who Experienced an Adverse Event | 9 | 2 |
An adverse event is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment.
| Participants | Gefapixant 45 mg | Placebo |
|---|---|---|
| Number of Participants Who Discontinued Study Treatment Due to an Adverse Event | 1 | 0 |
Cough frequency will be evaluated using a digital recording device which records sounds from the lungs and trachea through a chest contact sensor, as well as ambient sounds through a lapel microphone. Change from baseline in log-transformed 24-hour coughs per hour = log (24-hour coughs per hour at post-baseline) - log (24-hour coughs per hour at baseline). The denominators may be different if the recording period is actually \<24 hours but ≥20 hours).
| Coughs/hour | Gefapixant 45 mg | Placebo |
|---|---|---|
| Change From Baseline at Week 4 in Log-transformed 24-hour Coughs Per Hour | -0.23 ± 0.39 | -1.02 ± 0.38 |
Change from baseline at Week 4 in awake coughs per hour is the average hourly cough frequency (based on sound recordings) during the 24-hour monitoring period while the participant is awake. Change from baseline in log-transformed awake coughs per hour = log (awake coughs per hour at post-baseline) - log (awake coughs per hour at baseline) for the monitoring period the participant is awake.
| Coughs/hour | Gefapixant 45 mg | Placebo |
|---|---|---|
| Change From Baseline at Week 4 in Log-transformed Awake Coughs Per Hour | -0.20 ± 0.38 | -0.97 ± 0.37 |
Collected over Up to 6 weeks. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Gefapixant 45 mg | 0/11 (0%) | 0/11 (0%) | 9/11 (81.8%) |
| Placebo | 0/12 (0%) | 0/12 (0%) | 2/12 (16.7%) |
| Event | Gefapixant 45 mg | Placebo |
|---|---|---|
| DysgeusiaNervous system disorders | 7/11 | 0/12 |
| PalpitationsCardiac disorders | 1/11 | 0/12 |
| GastritisGastrointestinal disorders | 1/11 | 0/12 |
| Oral discomfortGastrointestinal disorders | 1/11 | 0/12 |
| Paraesthesia oralGastrointestinal disorders | 1/11 | 0/12 |
| ToothacheGastrointestinal disorders | 1/11 | 0/12 |
| NasopharyngitisInfections and infestations | 1/11 | 0/12 |
| PneumoniaInfections and infestations | 1/11 | 0/12 |
| Dermatitis contactSkin and subcutaneous tissue disorders | 1/11 | 0/12 |
| Drug eruptionSkin and subcutaneous tissue disorders | 1/11 | 0/12 |
| Age, Continuous(Years) | Gefapixant 45 mg | Placebo | Total |
|---|---|---|---|
| Mean | 54.5 ± 15.7 | 57.2 ± 11.7 | 55.9 ± 13.5 |
| Sex: Female, Male(Participants) | Gefapixant 45 mg | Placebo | Total |
|---|---|---|---|
| Female | 8 | 9 | 17 |
| Male | 3 | 3 | 6 |
| Race (NIH/OMB)(Participants) | Gefapixant 45 mg | Placebo | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 11 | 12 | 23 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 0 | 0 | 0 |
| White | 0 | 0 | 0 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Region of Enrollment(Participants) | Gefapixant 45 mg | Placebo | Total |
|---|---|---|---|
| Japan | 11 | 12 | 23 |
| 24-hour cough frequency(coughs/hour) | Gefapixant 45 mg | Placebo | Total |
|---|---|---|---|
| Mean | 40.1 ± 86.7 | 22.9 ± 20.5 | 31.1 ± 60.9 |
| Awake cough frequency(coughs/hour) | Gefapixant 45 mg | Placebo | Total |
|---|---|---|---|
| Mean | 49.0 ± 103.0 | 27.3 ± 21.0 | 37.7 ± 71.9 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — http://engagezone.msd.com/doc/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · engagezone.msd.com
Ran from Mar 2018 to primary completion in Jun 2018, 2 months.
Results were first posted in Jul 2019, 1 year after primary completion.
Of 25 phase 2 interventional studies under Chronic Cough, half reached primary completion within 11 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 21. This study's 2 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Oct 2019. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Gefapixant