Numerous clinical trials evaluate gefapixant across Early Phase 1 through Phase 3, primarily targeting refractory chronic cough, chronic cough, and idiopathic pulmonary fibrosis, alongside additional indications such as asthma, osteoarthritis, and renal insufficiency. Sponsored by major industry entities and academic institutions, these studies encompass completed, recruiting, unknown, and terminated protocols. Key investigations within this research landscape evaluate specialized outcomes, including cough reflex sensitivity and cough-related brain activity.
| NCT Number | Recruitment | Conditions | Sponsor/Collaborators | Start Date | Phases |
|---|---|---|---|---|---|
| NCT06542484 | RECRUITING | Chronic Cough |
Nagoya City University |
2024-12-04 | |
| NCT05813223 | UNKNOWN | Chronic Cough |
Stuart Mazzone |
2024-01-01 | EARLY_PHASE1 |
| NCT05813223 | Recruiting | Chronic Cough |
Stuart Mazzone|Merck Sharp & Dohme LLC|Melbourne Health|Monash University|University of Melbourne |
2024-01-01 | Early Phase 1 |
| NCT04525885 | COMPLETED | Chronic Cough |
Merck Sharp & Dohme LLC |
2019-05-17 | PHASE3 |
| NCT04193176 | COMPLETED | Chronic Cough |
Merck Sharp & Dohme LLC |
2020-05-10 | PHASE3 |
| NCT04193202 | COMPLETED | Chronic Cough |
Merck Sharp & Dohme LLC |
2020-05-21 | PHASE3 |
| NCT03696108 | COMPLETED | Chronic Cough |
Merck Sharp & Dohme LLC |
2018-10-31 | PHASE3 |
| NCT03449147 | COMPLETED | Chronic Cough |
Merck Sharp & Dohme LLC |
2018-03-15 | PHASE3 |
| NCT03654326 | COMPLETED | Endometriosis-related Pain |
Merck Sharp & Dohme LLC |
2018-09-11 | PHASE2 |
| NCT03449134 | COMPLETED | Chronic Cough |
Merck Sharp & Dohme LLC |
2018-03-14 | PHASE3 |
| NCT03882801 | COMPLETED | Obstructive Sleep Apnea (OSA) |
Merck Sharp & Dohme LLC |
2019-04-10 | PHASE1 |
| NCT03569033 | TERMINATED | Acute Cough |
Merck Sharp & Dohme LLC |
2018-07-04 | PHASE2 |
| NCT03482713 | COMPLETED | Chronic Cough |
Merck Sharp & Dohme LLC |
2018-03-16 | PHASE2 |
| NCT03108924 | COMPLETED | Renal Insufficiency |
Merck Sharp & Dohme LLC |
2017-04-14 | PHASE1 |
| NCT03108924 | Completed | Renal Insufficiency |
Merck Sharp & Dohme LLC |
2017-04-14 | Phase 1 |
| NCT02612610 | COMPLETED | Refractory Chronic Cough |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2015-12-15 | PHASE2 |
| NCT02476890 | COMPLETED | Refractory Chronic Cough |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2015-10-28 | PHASE2 |
| NCT02502097 | COMPLETED | Idiopathic Pulmonary Fibrosis; Cough |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2015-08-26 | PHASE2 |
| NCT02790840 | COMPLETED | Healthy |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2016-05-16 | PHASE1 |
| NCT02612623 | COMPLETED | Refractory Chronic Cough |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2015-12-17 | PHASE2 |
| NCT02790840 | Completed | Healthy |
Afferent Pharmaceuticals Inc. a subsidiary of Merck & Co. Inc. (Rahway New Jersey USA) |
2016-05-16 | Phase 1 |
| NCT02397460 | COMPLETED | Refractory Chronic Cough |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2015-04-29 | PHASE2 |
| NCT02349425 | COMPLETED | Refractory Chronic Cough |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2015-03-09 | PHASE2 |
| NCT02476890 | Completed | Refractory Chronic Cough |
Afferent Pharmaceuticals Inc. a subsidiary of Merck & Co. Inc. (Rahway New Jersey USA) |
2015-10-28 | Phase 2 |
| NCT02477709 | COMPLETED | Idiopathic Pulmonary Fibrosis |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2015-07-20 | PHASE2 |
| NCT02492776 | COMPLETED | Healthy |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2015-07-07 | PHASE1 |
| NCT02492776 | Completed | Healthy |
Afferent Pharmaceuticals Inc. a subsidiary of Merck & Co. Inc. (Rahway New Jersey USA)|Celerion |
2015-07-07 | Phase 1 |
| NCT02477709 | Completed | Idiopathic Pulmonary Fibrosis |
Afferent Pharmaceuticals Inc. a subsidiary of Merck & Co. Inc. (Rahway New Jersey USA) |
2015-07-20 | Phase 2 |
| NCT02229877 | COMPLETED | Healthy Volunteers |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2014-10-06 | PHASE1 |
| NCT01569438 | TERMINATED | Bladder Pain Syndrome |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2012-04-13 | PHASE2 |
| NCT01993329 | COMPLETED | Asthma |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2013-12-16 | PHASE2 |
| NCT01554579 | COMPLETED | Osteoarthritis of the Knee |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2012-03-29 | PHASE2 |
| NCT01432730 | COMPLETED | Chronic Cough |
Afferent Pharmaceuticals, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) |
2011-09-22 | PHASE2 |
(data from https://clinicaltrials.gov, updated on 2025-01-29)
Check the
Gefapixant
product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.
Mechanism and Biochemical Profile
Appendix RUO and cGMP Quality Standards
| Quality Dimension | RUO (Research Use Only) | cGMP (Current Good Manufacturing Practice) |
|---|---|---|
| Clinical Applicability | Prohibited in human clinical trials or medical diagnostics. | Mandatory for human clinical trials (Phase I–III) and therapies. |
| Regulatory Status | Non-regulated grade; exempt from drug manufacturing laws. | Legally enforced by health authorities (e.g., FDA, EMA, NMPA). |
| Facility Environment | Unclassified analytical or research laboratories. | Validated Cleanrooms (ISO Class 5–8) with continuous monitoring. |
| Quality Control | Basic purity and activity testing. | Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma). |
| Process Validation | Basic equipment calibration; no process validation required. | Full qualification (IQ/OQ/PQ) and complete batch records. |
| Quality Assurance | Vendor self-declared without required formal QMS. | Mandatory QA/QC unit, Change Control, CAPA, and vendor audits. |
| Regulatory Impact | High risk of IND rejection if used as a critical raw material. | Required for IND/NDA filings, supported by Drug Master Files (DMF). |
Footnotes
Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).
Note: Technical data last updated: Sep 1, 2026.