NCT02349425 is a Phase 2 clinical trial of Gefapixant in Refractory Chronic Cough, sponsored by Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA).

What drugs are being tested in NCT02349425?

Interventions in NCT02349425: Gefapixant, Placebo (for gefapixant).

What condition does NCT02349425 study?

NCT02349425 studies Refractory Chronic Cough.

Is NCT02349425 still recruiting?

NCT02349425 is currently completed. Last updated 22 October 2020.

Are results published for NCT02349425?

Yes — primary outcome results have been posted to ClinicalTrials.gov. See the outcomes section above for details.

Last reviewed 2020-10-22 · How we verify

NCT02349425

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

A Dose Escalation Study of Gefapixant (AF-219/MK-7264) in Refractory Chronic Cough (MK-7264-010)

Completed Phase 2 Results posted Last updated 22 October 2020

What this trial tests

Phase 2 trial testing Gefapixant in Refractory Chronic Cough in 59 participants. Completed in 9 February 2016.

Timeline

9 March 2015

Primary endpoint
1 February 2016

9 February 2016

Quick facts

Lead sponsor	Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)
Phase	Phase 2
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	crossover
Masking	quadruple
Primary purpose	treatment
Enrollment	59
Start date	9 March 2015
Primary completion	1 February 2016
Estimated completion	9 February 2016

Drugs / interventions tested

Gefapixant — full drug profile →
Placebo (for gefapixant) — full drug profile →

Conditions studied

Refractory Chronic Cough — all drugs for Refractory Chronic Cough →

Sponsor

Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) — full company profile →

Who can join

Adults 18 to 80, any sex, with Refractory Chronic Cough. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Change in Awake Objective Cough Frequency on Log-transformed Scale - Cohort 1 Primary · Period 1 (while awake): baseline (Day 0) and 24 hours after Day 4, 8, 12 & 16 doses; Period 2 (while awake): baseline (Day 22) and 24 hours after Day 26, 30, 34 and 38 doses

Awake Objective Frequency (per hour) is the total number of cough events during the monitoring period (in general, 24-hr interval) the participant is awake divided by the total duration (in hours) for the monitoring period the participant is awake. 24-hour sound recordings were collected using a digital recording device.

Group	Value	95% CI
Cohort 1 - Gefapixant 50 mg	0.56	0.43 – 0.72
Cohort 1 - Placebo for Gefapixant 50 mg	0.95	0.73 – 1.23
Cohort 1 - Gefapixant 100 mg	0.46	0.34 – 0.61
Cohort 1 - Placebo for Gefapixant 100 mg	0.95	0.71 – 1.28
Cohort 1 - Gefapixant 150 mg	0.48	0.35 – 0.65
Cohort 1 - Placebo for Gefapixant 150 mg	0.90	0.65 – 1.24
Cohort 1 - Gefapixant 200 mg	0.45	0.33 – 0.63
Cohort 1 - Placebo for Gefapixant 200 mg	1.06	0.75 – 1.48

Change in Awake Objective Cough Frequency on Log-transformed Scale - Cohort 2 Primary · Period 1 (while awake): baseline (Day 0) and 24 hours after Day 4, 8, 12 & 16 doses; Period 2 (while awake): baseline (Day 22) and 24 hours after Day 26, 30, 34 and 38 doses

Group	Value	95% CI
Cohort 2 - Gefapixant 7.5 mg	0.80	0.66 – 0.96
Cohort 2 - Placebo for Gefapixant 7.5 mg	0.93	0.77 – 1.13
Cohort 2 - Gefapixant 15 mg	0.67	0.57 – 0.80
Cohort 2 - Placebo for Gefapixant 15 mg	0.90	0.75 – 1.08
Cohort 2 - Gefapixant 30 mg	0.53	0.40 – 0.69
Cohort 2 - Placebo for Gefapixant 30 mg	0.84	0.64 – 1.10
Cohort 2 - Gefapixant 50 mg	0.44	0.32 – 0.60
Cohort 2 - Placebo for Gefapixant 50 mg	1.00	0.72 – 1.38

Percent Change From Baseline in Awake Cough Frequency for Cohort 1 Primary · Period 1 (while awake): baseline (Day 0) and 24 hours after Day 4, 8, 12 & 16 doses; Period 2 (while awake): baseline (Day 22) and 24 hours after Day 26, 30, 34 and 38 doses

Awake Objective Cough Frequency (per hour) is the total number of cough events during the monitoring period (in general, 24-hr interval) the participant is awake divided by the total duration (in hours) for the monitoring period the participant is awake. 24-hour sound recordings were collected using a digital recording device. Percent Change in Awake Cough Frequency is the change from baseline in awake cough frequency x 100, divided by baseline awake cough frequency. A negative result indicates a decrease in cough frequency, while a positive result indicates an increase in cough frequency.

Group	Value	95% CI
Cohort 1 - Gefapixant 50 mg	-20.6	± 84.29
Cohort 1' - Placebo for Gefapixant 50 mg	-0.1	± 33.75
Cohort 1 - Gefapixant 100 mg	-31.7	± 70.27
Cohort 1 - Placebo for Gefapixant 100 mg	1.9	± 35.18
Cohort 1 - Gefapixant 150 mg	-22.0	± 82.84
Cohort 1 - Placebo for Gefapixant 150 mg	-0.1	± 39.55
Cohort 1 - Gefapixant 200 mg	-27.9	± 57.03
Cohort 1 - Placebo for Gefapixant 200 mg	15.1	± 48.38

Percent Change From Baseline in Awake Cough Frequency for Cohort 2 Primary · Period 1 (while awake): baseline (Day 0) and 24 hours after Day 4, 8, 12 & 16 doses; Period 2 (while awake): baseline (Day 22) and 24 hours after Day 26, 30, 34 and 38 doses

Group	Value	95% CI
Cohort 2 - Gefapixant 7.5 mg	5.0	± 125.05
Cohort 2 - Placebo for Gefapixant 7.5 mg	-3.8	± 36.13
Cohort 2 - Gefapixant 15 mg	-21.4	± 39.32
Cohort 2 - Placebo for Gefapixant 15 mg	-6.4	± 33.78
Cohort 2 - Gefapixant 30 mg	-26.3	± 61.01
Cohort 2 - Placebo for Gefapixant 30 mg	-1.1	± 64.38
Cohort 2 - Gefapixant 50 mg	-28.1	± 74.90
Cohort 2 - Placebo for Gefapixant 50 mg	23.1	± 92.60

Responder Analysis of Awake Cough Frequency for Cohort 1 Primary · Period 1 (while awake): baseline (Day 0) and 24 hours after Day 4, 8, 12 & 16 doses; Period 2 (while awake): baseline (Day 22) and 24 hours after Day 26, 30, 34 and 38 doses

Participants were classified as responders based on the magnitude of the percent change from baseline in Awake Objective cough frequency: 1. ≥70% Reduction=1 if Percent Change from Baseline in cough frequency at the end of the dosing interval ≤-70.0%; 0 Otherwise; 2. ≥50% Reduction=1 if Percent Change from Baseline in cough frequency at the end of the dosing interval ≤ -50.0%; 0 Otherwise; 3. ≥30% Reduction=1 if Percent Change from Baseline in cough frequency at the end of the dosing interval ≤ -30.0%; 0 Otherwise. These responder definitions were not mutually exclusive. A participant who achi

% Reduction ≥70

Group	Value	95% CI
Cohort 1 - Gefapixant 50 mg	34.6
Cohort 1 - Placebo for Gefapixant 50 mg	0
Cohort 1 - Gefapixant 100 mg	33.3
Cohort 1 - Placebo for Gefapixant 100 mg	0
Cohort 1 - Gefapixant 150 mg	34.8
Cohort 1 - Placebo for Gefapixant 150 mg	4.5
Cohort 1 - Gefapixant 200 mg	32.0
Cohort 1 - Placebo for Gefapixant 200 mg	0

% Reduction ≥50

Group	Value	95% CI
Cohort 1 - Gefapixant 50 mg	46.2
Cohort 1 - Placebo for Gefapixant 50 mg	0
Cohort 1 - Gefapixant 100 mg	50.0
Cohort 1 - Placebo for Gefapixant 100 mg	4.0
Cohort 1 - Gefapixant 150 mg	47.8
Cohort 1 - Placebo for Gefapixant 150 mg	4.5
Cohort 1 - Gefapixant 200 mg	44.0
Cohort 1 - Placebo for Gefapixant 200 mg	0

% Reduction ≥30

Group	Value	95% CI
Cohort 1 - Gefapixant 50 mg	53.8
Cohort 1 - Placebo for Gefapixant 50 mg	12.0
Cohort 1 - Gefapixant 100 mg	66.7
Cohort 1 - Placebo for Gefapixant 100 mg	16.0
Cohort 1 - Gefapixant 150 mg	65.2
Cohort 1 - Placebo for Gefapixant 150 mg	22.7
Cohort 1 - Gefapixant 200 mg	56.0
Cohort 1 - Placebo for Gefapixant 200 mg	16.0

Responder Analysis of Awake Cough Frequency for Cohort 2 Primary · Period 1 (while awake): baseline (Day 0) and 24 hours after Day 4, 8, 12 & 16 doses; Period 2 (while awake): baseline (Day 22) and 24 hours after Day 26, 30, 34 and 38 doses

% Reduction ≥70

Group	Value	95% CI
Cohort 2 - Gefapixant 7.5 mg	3.4
Cohort 2 - Placebo for Gefapixant 7.5 mg	3.6
Cohort 2 - Gefapixant 15 mg	10.0
Cohort 2 - Placebo for Gefapixant 15 mg	0
Cohort 2 - Gefapixant 30 mg	20.7
Cohort 2 - Placebo for Gefapixant 30 mg	3.4
Cohort 2 - Gefapixant 50 mg	31.0
Cohort 2 - Placebo for Gefapixant 50 mg	3.7

% Reduction ≥50

Group	Value	95% CI
Cohort 2 - Gefapixant 7.5 mg	13.8
Cohort 2 - Placebo for Gefapixant 7.5 mg	7.1
Cohort 2 - Gefapixant 15 mg	20.0
Cohort 2 - Placebo for Gefapixant 15 mg	6.9
Cohort 2 - Gefapixant 30 mg	31.0
Cohort 2 - Placebo for Gefapixant 30 mg	17.2
Cohort 2 - Gefapixant 50 mg	41.4
Cohort 2 - Placebo for Gefapixant 50 mg	11.1

% Reduction ≥30

Group	Value	95% CI
Cohort 2 - Gefapixant 7.5 mg	37.9
Cohort 2 - Placebo for Gefapixant 7.5 mg	14.3
Cohort 2 - Gefapixant 15 mg	46.7
Cohort 2 - Placebo for Gefapixant 15 mg	20.7
Cohort 2 - Gefapixant 30 mg	62.1
Cohort 2 - Placebo for Gefapixant 30 mg	31.0
Cohort 2 - Gefapixant 50 mg	55.2
Cohort 2 - Placebo for Gefapixant 50 mg	22.2

Change From Baseline in Awake (0-8 Hours) Objective Cough Frequency for Cohort 1 Secondary · Period 1 (while awake): baseline (Day 0) and 0-8 hours after Day 4, 8, 12 & 16 doses; Period 2 (while awake): baseline (Day 22) and 0-8 hours after Day 26, 30, 34 and 38 doses

Awake (0-8 hours) Objective Cough Frequency is the total number of cough events during the monitoring period the participant was awake for the first 8 hours after the participant took their study medication divided by 8 or the total duration (in hours) for the monitoring period the participant was awake whichever is less. 24-hour sound recordings were collected using a digital recording device. Results are change from baseline: a negative result indicates a decrease in cough frequency, while a positive result indicates an increase in cough frequency. Cough frequency was analyzed using a mixed

Group	Value	95% CI
Cohort 1 - Gefapixant 50 mg	-24.5	-33.0 – -15.9
Cohort 1 - Placebo for Gefapixant 50 mg	-5.5	-14.2 – 3.3
Cohort 1 - Gefapixant 100 mg	-24.5	-33.1 – -15.8
Cohort 1 - Placebo for Gefapixant 100 mg	-0.1	-8.8 – 8.7
Cohort 1 - Gefapixant 150 mg	-26.5	-40.3 – -12.8
Cohort 1 - Placebo for Gefapixant 150 mg	2.7	-11.4 – 16.9
Cohort 1 - Gefapixant 200 mg	-27.5	-37.9 – -17.0
Cohort 1 - Placebo for Gefapixant 200 mg	2.2	-8.5 – 12.8

Change From Baseline in Awake (0-8 Hours) Objective Cough Frequency for Cohort 2 Secondary · Period 1 (while awake): baseline (Day 0) and 0-8 hours after Day 4, 8, 12 & 16 doses; Period 2 (while awake): baseline (Day 22) and 0-8 hours after Day 26, 30, 34 and 38 doses

Group	Value	95% CI
Cohort 2 - Gefapixant 7.5 mg	-8.0	-17.9 – 1.9
Cohort 2 - Placebo for Gefapixant 7.5 mg	-1.1	-11.1 – 9.0
Cohort 2 - Gefapixant 15 mg	-15.2	-22.1 – -8.3
Cohort 2 - Placebo for Gefapixant 15 mg	-1.7	-8.8 – 5.3
Cohort 2 - Gefapixant 30 mg	-21.7	-31.9 – -11.5
Cohort 2 - Placebo for Gefapixant 30 mg	8.5	-1.8 – 18.8
Cohort 2 - Gefapixant 50 mg	-21.9	-32.8 – -11.0
Cohort 2 - Placebo for Gefapixant 50 mg	4.7	-6.5 – 16.0

Change From Baseline in Total (24 Hours) Cough Frequency - Cohort 1 Secondary · Period 1: baseline (Day 0) and 0-24 hours after Day 4, 8, 12 & 16 doses; Period 2: baseline (Day 22) and 0-24 hours after Day 26, 30, 34 and 38 doses

Total (0-24 hours) Objective Cough Frequency is the total number of cough events during the monitoring period divided by the total duration (in hours, i.e., 24 hours mostly) for the monitoring period. 24-hour sound recordings were collected using a digital recording device. Results are change from baseline: a negative result indicates a decrease in cough frequency, while a positive result indicates an increase in cough frequency. Cough frequency was analyzed using MMRM to evaluate the results of the 2-period cross-over study. The derived change measured at each dose were the repeated measures

Group	Value	95% CI
Cohort 1 - Gefapixant 50 mg	-16.6	-22.4 – -10.9
Cohort 1 - Placebo for Gefapixant 50 mg	-1.5	-7.5 – 4.5
Cohort 1 - Gefapixant 100 mg	-17.6	-24.1 – -11.0
Cohort 1 - Placebo for Gefapixant 100 mg	-0.9	-7.5 – 5.8
Cohort 1 - Gefapixant 150 mg	-18.0	-26.1 – -9.9
Cohort 1 - Placebo for Gefapixant 150 mg	1.5	-6.8 – 9.8
Cohort 1 - Gefapixant 200 mg	-17.4	-25.2 – -9.5
Cohort 1 - Placebo for Gefapixant 200 mg	3.1	-4.9 – 11.2

Change From Baseline in Total (24 Hours) Cough Frequency - Cohort 2 Secondary · Period 1: baseline (Day 0) and 0-24 hours after Day 4, 8, 12 & 16 doses; Period 2: baseline (Day 22) and 0-24 hours after Day 26, 30, 34 and 38 doses

Group	Value	95% CI
Cohort 2 - Gefapixant 7.5 mg	-6.9	-12.6 – -1.1
Cohort 2 - Placebo for Gefapixant 7.5 mg	-2.7	-8.6 – 3.1
Cohort 2 - Gefapixant 15 mg	-11.0	-15.5 – -6.4
Cohort 2 - Placebo for Gefapixant 15 mg	-3.8	-8.4 – 0.9
Cohort 2 - Gefapixant 30 mg	-16.9	-23.3 – -10.4
Cohort 2 - Placebo for Gefapixant 30 mg	1.4	-5.2 – 7.9
Cohort 2 - Gefapixant 50 mg	-15.9	-21.0 – -9.9
Cohort 2 - Placebo for Gefapixant 50 mg	1.8	-4.4 – 7.9

Change From Baseline in Sleep Cough Frequency - Cohort 1 Secondary · Period 1 (while asleep): baseline (Day 0) and 24 hours after Day 4, 8, 12 & 16 doses; Period 2 (while asleep): baseline (Day 22) and 24 hours after Day 26, 30, 34 and 38 doses

Sleep Objective Cough Frequency is the total number of cough events during the monitoring period the participant is asleep divided by the total duration (in hours) for the monitoring period the participant is asleep. 24-hour sound recording were collected with a digital recording device. Results are change from baseline: a negative result indicates a decrease in cough frequency, while a positive result indicates an increase in cough frequency. Cough frequency was analyzed using MMRM to evaluate the results of the 2-period cross-over study. The derived change measured at each dose were the rep

Group	Value	95% CI
Cohort 1 - Gefapixant 50 mg	-3.5	-7.0 – 0.1
Cohort 1 - Placebo for Gefapixant 50 mg	0.1	-3.5 – 3.7
Cohort 1 - Gefapixant 100 mg	-3.1	-6.8 – 0.6
Cohort 1 - Placebo for Gefapixant 100 mg	-0.7	-4.2 – 2.8
Cohort 1 - Gefapixant 150 mg	-2.0	-4.8 – 0.7
Cohort 1 - Placebo for Gefapixant 150 mg	-0.1	-2.8 – 2.6
Cohort 1 - Gefapixant 200 mg	-3.6	-7.0 – -0.1
Cohort 1 - Placebo for Gefapixant 200 mg	0.2	-3.2 – 3.6

Change From Baseline in Sleep Cough Frequency - Cohort 2 Secondary · Period 1 (while asleep): baseline (Day 0) and 24 hours after Day 4, 8, 12 & 16 doses; Period 2 (while asleep): baseline (Day 22) and 24 hours after Day 26, 30, 34 and 38 doses

Group	Value	95% CI
Cohort 2 - Gefapixant 7.5 mg	0.6	-2.7 – 3.9
Cohort 2 - Placebo for Gefapixant 7.5 mg	-0.6	-3.9 – 2.8
Cohort 2 - Gefapixant 15 mg	-3.1	-5.6 – -0.5
Cohort 2 - Placebo for Gefapixant 15 mg	-2.5	-5.1 – 0.2
Cohort 2 - Gefapixant 30 mg	-2.4	-4.7 – -0.2
Cohort 2 - Placebo for Gefapixant 30 mg	-1.6	-3.8 – 0.7
Cohort 2 - Gefapixant 50 mg	-3.0	-8.7 – 2.6
Cohort 2 - Placebo for Gefapixant 50 mg	2.1	-3.6 – 7.9

Adverse events — posted to ClinicalTrials.gov

Time frame: Adverse event data collection is up to 11 weeks All-cause mortality is up to 22 weeks. Reporting threshold: 5%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Cohort 1: Gefapixant 50 mg

Serious: 0/28 (0%)

Deaths: 0/28

Cohort 1: Gefapixant 100 mg

Serious: 1/28 (4%)

Deaths: 0/28

Cohort 1 - Gefapixant 150 mg

Serious: 0/26 (0%)

Deaths: 0/26

Cohort 1: Gefapixant 200 mg

Serious: 0/26 (0%)

Deaths: 0/26

Cohort 1 - Placebo

Serious: 1/28 (4%)

Deaths: 0/28

Cohort 2 - Gefapixant 7.5 mg

Serious: 0/30 (0%)

Deaths: 0/30

Cohort 2 - Gefapixant 15 mg

Serious: 0/30 (0%)

Deaths: 0/30

Cohort 2 - Gefapixant 30 mg

Serious: 0/30 (0%)

Deaths: 0/30

Cohort 2 - Gefapixant 50 mg

Serious: 1/30 (3%)

Deaths: 0/30

Cohort 2- Placebo

Serious: 0/29 (0%)

Deaths: 0/29

Serious adverse events (5 terms)

Reaction	System	Cohort 1: Gefapixant 50 mg	Cohort 1: Gefapixant 100 mg	Cohort 1 - Gefapixant 150 mg	Cohort 1: Gefapixant 200 mg	Cohort 1 - Placebo	Cohort 2 - Gefapixant 7.5 mg	Cohort 2 - Gefapixant 15 mg	Cohort 2 - Gefapixant 30 mg	Cohort 2 - Gefapixant 50 mg	Cohort 2- Placebo
Blood creatinine increased	Investigations	—	—	—	—	—	—	—	—	—	—
Dehydration	Metabolism and nutrition disorders	—	—	—	—	—	—	—	—	—	—
Invasive ductal breast carcinoma	Neoplasms benign, malignant and unspecified (incl cysts and polyps)	—	—	—	—	—	—	—	—	—	—
Cerebrovascular accident	Nervous system disorders	—	—	—	—	—	—	—	—	—	—
Presyncope	Nervous system disorders	—	—	—	—	—	—	—	—	—	—

Other adverse events (12 terms — click to expand)

Reaction	System	Cohort 1: Gefapixant 50 mg	Cohort 1: Gefapixant 100 mg	Cohort 1 - Gefapixant 150 mg	Cohort 1: Gefapixant 200 mg	Cohort 1 - Placebo	Cohort 2 - Gefapixant 7.5 mg	Cohort 2 - Gefapixant 15 mg	Cohort 2 - Gefapixant 30 mg	Cohort 2 - Gefapixant 50 mg	Cohort 2- Placebo
Dysgeusia	Nervous system disorders	—	—	—	—	—	—	—	—	—	—
Upper respiratory tract infection	Infections and infestations	—	—	—	—	—	—	—	—	—	—
Dry mouth	Gastrointestinal disorders	—	—	—	—	—	—	—	—	—	—
Hypoaesthesia oral	Gastrointestinal disorders	—	—	—	—	—	—	—	—	—	—
Paraesthesia oral	Gastrointestinal disorders	—	—	—	—	—	—	—	—	—	—
Rhinitis	Infections and infestations	—	—	—	—	—	—	—	—	—	—
Viral upper respiratory tract infection	Infections and infestations	—	—	—	—	—	—	—	—	—	—
Urine output decreased	Investigations	—	—	—	—	—	—	—	—	—	—
Flank pain	Musculoskeletal and connective tissue disorders	—	—	—	—	—	—	—	—	—	—
Ageusia	Nervous system disorders	—	—	—	—	—	—	—	—	—	—
Hypogeusia	Nervous system disorders	—	—	—	—	—	—	—	—	—	—
Nasal dryness	Respiratory, thoracic and mediastinal disorders	—	—	—	—	—	—	—	—	—	—

Most-reported serious reactions: Blood creatinine increased, Dehydration, Invasive ductal breast carcinoma, Cerebrovascular accident, Presyncope.

Data from ClinicalTrials.gov NCT02349425 adverse events section.

Sponsor's own description

A randomized, double-blind, placebo-controlled, crossover, dose escalation study to assess the efficacy and tolerability of gefapixant (AF-219; MK-7264) in participants with refractory chronic cough.

Publications & conference data

7 peer-reviewed publications reference this trial (live from Europe PMC):

Mechanisms and Rationale for Targeted Therapies in Refractory and Unexplained Chronic Cough.
Mazzone SB, McGarvey L. · · 2021 · cited 73× · PMID 32748976 · DOI 10.1002/cpt.2003
Design and rationale of two phase 3 randomised controlled trials (COUGH-1 and COUGH-2) of gefapixant, a P2X3 receptor antagonist, in refractory or unexplained chronic cough.
Muccino DR, Morice AH, Birring SS, Dicpinigaitis PV, et al · · 2020 · cited 46× · PMID 33263037 · DOI 10.1183/23120541.00284-2020
Efficacy and Tolerability of Gefapixant for Treatment of Refractory or Unexplained Chronic Cough: A Systematic Review and Dose-Response Meta-Analysis.
Kum E, Patel M, Diab N, Wahab M, et al · · 2023 · cited 27× · PMID 37694849 · DOI 10.1001/jama.2023.18035
Basic/Translational Development of Forthcoming Opioid- and Nonopioid-Targeted Pain Therapeutics.
Knezevic NN, Yekkirala A, Yaksh TL. · · 2017 · cited 24× · PMID 29049116 · DOI 10.1213/ane.0000000000002442
Safety and efficacy of gefapixant, a novel drug for the treatment of chronic cough: A systematic review and meta-analysis of randomized controlled trials.
Abu-Zaid A, Aljaili AK, Althaqib A, Adem F, et al · · 2021 · cited 12× · PMID 34012479 · DOI 10.4103/atm.atm_417_20
Decoding the impact of the placebo response in clinical trials for chronic cough.
Zhang M, Zhang B, Morice AH. · · 2024 · cited 6× · PMID 39469270 · DOI 10.1183/23120541.00335-2024
Systematic literature review of treatments used for refractory or unexplained chronic cough in adults.
Bali V, Kardos P, Page C, Rogliani P, et al · · 2024 · cited 5× · PMID 38444993 · DOI 10.4103/atm.atm_105_23

Verify or expand the search:

Other trials of Gefapixant

Trials testing the same drug.

NCT05813223 — Effect of Gefapixant on Cough-related Brain Activity in Patients With Chronic Cough · EARLY_PHASE1 · recruiting
NCT04193202 — Efficacy and Safety of Gefapixant (MK-7264) in Adult Participants With Recent Onset Chronic Cough (MK-7264-043) · Phase 3 · completed
NCT04193176 — Efficacy and Safety of Gefapixant (MK-7264) in Women With Chronic Cough and Stress Urinary Incontinence (MK-7264-042) · Phase 3 · completed
NCT03882801 — Safety and Tolerability of Gefapixant (MK-7264) in Participants With Obstructive Sleep Apnea (MK-7264-039) · Phase 1 · completed
NCT03696108 — A Study of Gefapixant (MK-7264) in Japanese Adult Participants With Refractory or Unexplained Chronic Cough (MK-7264-038 · Phase 3 · completed

Other recruiting trials for Refractory Chronic Cough

Currently open trials in the same condition.

NCT06706765 — Group Telehealth Behavioral Cough Suppression Therapy · EARLY_PHASE1 · recruiting
NCT05600777 — A 24-Week Study of the Efficacy and Safety of BLU-5937 in Adults With Refractory Chronic Cough · Phase 3 · active not recruiting
NCT05599191 — A 52-Week Study of the Efficacy and Safety of BLU-5937 in Adults With Refractory Chronic Cough · Phase 3 · active not recruiting

Other Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) trials

Trials by the same sponsor.

NCT02790840 — A Multiple-Dose Pharmacokinetics Study of Three Gefapixant (AF-219/MK-7264) Formulations · Phase 1 · completed
NCT02612623 — An 8-Week Refractory Chronic Cough Study (MK-7264-021) · Phase 2 · completed
NCT02612610 — A 12-Week Study in Participants With Refractory Chronic Cough (MK-7264-012) · Phase 2 · completed
NCT02476890 — Effect of Gefapixant (MK-7264/AF-219) on Cough Reflex Sensitivity in Healthy and Chronic Cough Participants (MK-7264-014 · Phase 2 · completed
NCT02502097 — A Study of Gefapixant (AF-219/MK-7264) in Participants With Idiopathic Pulmonary Fibrosis (IPF) With Persistent Cough (M · Phase 2 · completed

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT02349425 (US National Library of Medicine, public domain)
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)
Last refreshed: 22 October 2020

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT02349425.

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NCT02349425

Quick facts

Drugs / interventions tested

Conditions studied

Sponsor

Who can join

Results — posted to ClinicalTrials.gov

Adverse events — posted to ClinicalTrials.gov

Serious adverse events (5 terms)

Sponsor's own description

Publications & conference data

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