Drug

Gefapixant

Approved medicine

ClassP2X purinoceptor 3 antagonistResearchActive indication expansion

RxNorm2169701 ChEMBLCHEMBL3716057 ATCR05DB29UNII6K6L7E3F1L

Research papers

P2X purinoceptor 3

Primary target

Regulatory events

Latest activity

beta

Recent clinical, regulatory, research and industry developments relating to this drug.

The Effect of Acute and Prolonged Administration of Gefapixant on Cough-related Brain Activity in Patients With Chronic Cough

Clinical trial2025-10-31Primary completion · ClinicalTrials.gov

Gefapixant as a P2X3 receptor antagonist treatment for obstructive sleep apnea: a randomized controlled trial.

Research2024-12-01Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine

A Phase 3b Randomized, Double-blind, Placebo Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Gefapixant in Women With Chronic Cough and Stress Urinary Incontinence

Clinical trial2024-11-05Results posted · ClinicalTrials.gov

A Phase 2a, Proof of Concept, Randomized, Double-Blind, Placebo-Controlled Clinical Trial, to Evaluate the Efficacy and Safety of MK-7264 in Women With Moderate to Severe Endometriosis-Related Pain

Clinical trial2024-11-04Results posted · ClinicalTrials.gov

A Randomized Double Blind Clinical Trial to Evaluate the Effects of MK-7264 in Participants With Obstructive Sleep Apnea

Clinical trial2024-11-04Results posted · ClinicalTrials.gov

Randomized, controlled, proof-of-concept trial of gefapixant for endometriosis-related pain.

Research2024-09-12Fertility and sterility

Efficacy and safety of gefapixant in women with chronic cough and cough-induced stress urinary incontinence: a phase 3b, randomised, multicentre, double-blind, placebo-controlled trial.

Research2024-08-30The Lancet. Respiratory medicine

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, 12-Month Study to Evaluate the Efficacy and Safety of MK-7264 in Adult Participants With Chronic Cough (PN030)

Clinical trial2024-01-12Results posted · ClinicalTrials.gov

Approval: Lyfnua (EMA)

Regulatory2023-09-15EMA

A Phase 3b Randomized, Double-blind, Placebo Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Gefapixant in Adult Participants With Recent Onset Chronic Cough

Clinical trial2023-05-16Results posted · ClinicalTrials.gov

The Efficacy and Safety of Gefapixant in a Phase 3b Trial of Patients with Recent-Onset Chronic Cough.

Research2023-03-06Lung

An Open-Label, Single-Dose Study to Investigate the Influence of Renal Insufficiency on the Pharmacokinetics of MK-7264

Clinical trial2022-07-27Results posted · ClinicalTrials.gov

Profile

Identifiers & mechanism

Canonical identifiers, marketed brand names and mechanism, resolved across RxNorm, ChEMBL and ATC.

Canonical name

Gefapixant

RxNorm CUI

2169701

ChEMBL ID

CHEMBL3716057

ATC codes

R05DB29

UNII

6K6L7E3F1L

Primary mechanism

P2X purinoceptor 3 antagonist

Regulatory jurisdictions

ema

Pharmacology & targets

1 target

Known molecular targets and mechanisms supported by curated pharmacology databases.

P2X purinoceptor 3

P2RX3 · P56373

ANTAGONISTP2X purinoceptor 3 antagonist

Regulatory timeline

1 event

The complete regulatory record, grouped by authority — approvals, safety advisories and label changes. Each authority shows its most recent events; expand one to read its full history.

Earliest approval

2023-09-15

Latest approval

2023-09-15

Authorities

EMA

Total events

emaEuropean Medicines Agency· 1 event

2023-09-15Approval

Approval: Lyfnua (EMA)

Indication: Lyfnua is indicated in adults for the treatment of refractory or unexplained chronic cough.

Evidence ↗

Contains information from the European Medicines Agency (European Medicines Agency), © EMA, reused under CC BY 4.0.

Clinical trials

25 trials

The current development programme across all trial phases — status mix, phase distribution and the late-stage studies shaping the evidence base.

Development programme

CLINICALTRIALS.GOV · LIVE REGISTRY

registered trials across all phases

LATEST COMPLETION 2022

Late-stage (III+)

Completed

Discontinued

PHASE DISTRIBUTIONn = 25

Early Phase 11Phase 15Phase 214Phase 35

Late-stage studies

Phase III+ trials still open or recently active — where late-stage evidence is being generated.

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, 12-Month Study to Evaluate the Efficacy and Safety of MK-7264 in Adult Participants With Chronic Cough (PN030)

CompletedPH IIIMerck Sharp & Dohme LLCn=1612022

A Phase 3b Randomized, Double-blind, Placebo Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Gefapixant in Women With Chronic Cough and Stress Urinary Incontinence

CompletedPH IIIMerck Sharp & Dohme LLCn=3762022

A Phase 3b Randomized, Double-blind, Placebo Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Gefapixant in Adult Participants With Recent Onset Chronic Cough

CompletedPH IIIMerck Sharp & Dohme LLCn=4192021

A Phase 3, Randomized, Double-blind Clinical Study to Evaluate the Long-term Safety and Efficacy of MK-7264 in Japanese Adult Participants With Refractory or Unexplained Chronic Cough

CompletedPH IIIMerck Sharp & Dohme LLCn=1752020

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, 12-Month Study to Evaluate the Efficacy and Safety of MK-7264 in Adult Participants With Chronic Cough (PN027)

CompletedPH IIIMerck Sharp & Dohme LLCn=7322020

Recent completions

Trials that read out recently, adding to the completed evidence base.

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, 12-Month Study to Evaluate the Efficacy and Safety of MK-7264 in Adult Participants With Chronic Cough (PN030)

CompletedPH IIIMerck Sharp & Dohme LLCn=1612022

A Phase 3b Randomized, Double-blind, Placebo Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Gefapixant in Women With Chronic Cough and Stress Urinary Incontinence

CompletedPH IIIMerck Sharp & Dohme LLCn=3762022

A Phase 3b Randomized, Double-blind, Placebo Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Gefapixant in Adult Participants With Recent Onset Chronic Cough

CompletedPH IIIMerck Sharp & Dohme LLCn=4192021

A Phase 3, Randomized, Double-blind Clinical Study to Evaluate the Long-term Safety and Efficacy of MK-7264 in Japanese Adult Participants With Refractory or Unexplained Chronic Cough

CompletedPH IIIMerck Sharp & Dohme LLCn=1752020

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, 12-Month Study to Evaluate the Efficacy and Safety of MK-7264 in Adult Participants With Chronic Cough (PN027)

CompletedPH IIIMerck Sharp & Dohme LLCn=7322020

A Phase 2a, Proof of Concept, Randomized, Double-Blind, Placebo-Controlled Clinical Trial, to Evaluate the Efficacy and Safety of MK-7264 in Women With Moderate to Severe Endometriosis-Related Pain

CompletedPH IIMerck Sharp & Dohme LLCn=1872020

Research activity

6 papers

Key research shaping understanding of this drug, combining the latest publications with the most influential evidence.

Publications over time

20202025

Most influential

Gefapixant in two randomised dose-escalation studies in chronic cough.

The European respiratory journal · 2020 · 98 cites

The Efficacy and Safety of Gefapixant in a Phase 3b Trial of Patients with Recent-Onset Chronic Cough.

Lung · 2023 · 25 cites

Randomized, controlled, proof-of-concept trial of gefapixant for endometriosis-related pain.

Fertility and sterility · 2025 · 6 cites

Effects of Renal Impairment on the Pharmacokinetics of Gefapixant, a P2X3 Receptor Antagonist.

Journal of clinical pharmacology · 2022 · 4 cites

Gefapixant as a P2X3 receptor antagonist treatment for obstructive sleep apnea: a randomized controlled trial.

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2024 · 3 cites

Efficacy and safety of gefapixant in women with chronic cough and cough-induced stress urinary incontinence: a phase 3b, randomised, multicentre, double-blind, placebo-controlled trial.

The Lancet. Respiratory medicine · 2024 · 2 cites