Medical Information Only. Always consult your healthcare provider before enrolling in any clinical trial.
NCT03449147 · ClinicalTrials.gov registry record · Phase 3
A Study of Gefapixant (MK-7264) in Adult Participants With Chronic Cough (MK-7264-030)
A Phase 3 study, sponsored by Merck Sharp & Dohme.
- Completed
- Registry status
- Phase 3
- Development phase
- 1,317
- Enrollment target
NCT03449147: Completed Phase 3 study, sponsored by Merck Sharp & Dohme.
NCT03449147 is a Phase 3 study that has completed, run by Merck Sharp & Dohme. The registered enrollment target is 1,317 participants, above the 772-participant average among 15,282 other Phase 3 trials with a reported enrollment target (71% higher). According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT03449147, a Phase 3 study, has completed, sponsored by Merck Sharp & Dohme.
- COMPLETED
- Registry status
- Phase 3
- Development phase
- 1,317 participants
- Enrollment target
Study Summary
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.
Primary Outcome
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.
Interventions
- DRUG Placebo
- DRUG Gefapixant 15 mg BID
- DRUG Gefapixant 45 mg BID
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 1,317 participants |
| Start Date | 2018-03-15 |
| Est. Completion | 2020-10-30 |
| Phase | Phase 3 |
What the finished NCT03449147 record still lists
NCT03449147 is an interventional study that assigns participants to a tested intervention. Its 1,317 participants enrollment target places it among the larger protocols in the corpus, above the 772-participant average among 15,282 other Phase 3 trials with a reported enrollment target (71% higher).
The record links to 0 conditions, and to 3 interventions - of which Placebo is the first listed.
NCT03449147 does not publish any study locations in the registry export this page uses.
Frequently Asked Questions
What is clinical trial NCT03449147 about?
NCT03449147 is a clinical study titled "A Study of Gefapixant (MK-7264) in Adult Participants With Chronic Cough (MK-7264-030)". 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 i...
What is the current status of trial NCT03449147?
This trial is currently completed. It is a Phase 3 study. The enrollment target is 1,317 participants. The study started on 2018-03-15. Estimated completion is 2020-10-30.
What interventions are being tested in trial NCT03449147?
The interventions under investigation include: Placebo (DRUG), Gefapixant 15 mg BID (DRUG), Gefapixant 45 mg BID (DRUG).
Who is sponsoring clinical trial NCT03449147?
This trial is sponsored by Merck Sharp & Dohme, which has 558 total clinical trials registered on ClinicalTrials.gov.
Learn More About Clinical Trials
How this trial's enrollment target compares
Where NCT03449147's enrollment target sits among peer trials
1,317 185th of 2000 higher than 1,816 of 2,000 other Phase 3 trials
participants (enrollment target), bucketed by value
Each bar is a band; taller bars hold more other Phase 3 trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov registry export · 2026-08-08
Nationwide trials with similar profiles
Cross-condition peers matched on enrollment target and registry start date, not the same-condition list above.
Similar enrollment target
- NCT05762302 · 1,316 participants · NA
The Impact of MeMed BV® on Management of Patients With Suspected Lower Respiratory Tract Infections (LRTI) in the Emergency Department (ED) and Urgent Care Center (UCC) ("JUPITER" TRIAL)
- NCT07144800 · 1,319 participants · NA
Family COMIDA (Consumo de Opciones Más Ideales De Alimentos) (Eating More Ideal Food Options)
- NCT06557005 · 1,320 participants · NA
Facilitated Transitions From Postpartum to Primary Care Coordination for People With Chronic Conditions
- NCT07213908 · 1,320 participants · NA
Comparing Two School-Based Sleep Health Interventions To Promote Sleep Quality in Youth
Similar registry start date
- NCT05962346 · started 2026-12 · NA
Fetal Endoscopic Tracheal Occlusion for Congenital Diaphragmatic Hernia
- NCT07125183 · started 2026-12 · Phase 2
Study on Efficacy and Tolerability of Weekly Doxorubicin in Elderly Patients With Advanced or Metastatic Leiomyosarcoma
- NCT07292298 · started 2026-11 · Phase 2
Phase 2 Single-Arm Rectal Cancer Brachytherapy for Patients With Low-Lying Residual Adenocarcinoma After Total Neoadjuvant Therapy to Improve Organ Preservation Rates
- NCT04263285 · started 2026-10 · NA
Treatment of Depression Post-SCI