Clinical trial NCT03449147: A Study of Gefapixant (MK-7264) in Adult Participants With Chronic Cough (MK-7264-030)
Official title: 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)
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE3
Conditions: Chronic Cough
Lead sponsor: Merck Sharp & Dohme LLC
Sponsor class: INDUSTRY
First posted: 2018-02-28
Enrollment: 1317
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants with refractory or unexplained chronic cough will be randomized to 1 of 3 treatment groups: gefapixant 45 mg twice daily (BID), gefapixant 15 mg BID, or placebo.
Primary purpose: TREATMENT

Brief 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.

Detailed description: This study will have a main 24-week treatment period and a 28-week extension period of treatment (total treatment period of 52 weeks). Participants at selected sites and countries who complete the main and extension study periods may consent to participate in an observational, 12-week, Off-treatment Durability Study Period. Any assessments conducted in the observational period will be exploratory.

Eligibility criteria: Inclusion Criteria:

* Chest radiograph or computed tomography scan of the thorax (within 5 years of Screening/Visit 1 and after the onset of chronic cough) not demonstrating any abnormality considered to be significantly contributing to the chronic cough or any other clinically significant lung disease in the opinion of the principal investigator or the sub-investigator
* Has had chronic cough for at least 1 year with a diagnosis of refractory chronic cough or unexplained chronic cough
* Is a female who is not pregnant, not breastfeeding, not of childbearing potential, or agrees to follow contraceptive guidance
* Provides written informed consent and is willing and able to comply with the study protocol (including use of the digital cough recording device and completion of study questionnaires)

Exclusion Criteria:

* Is a current smoker or has given up smoking within 12 months of Screening, or is a former smoker with greater than 20 pack-years
* Has a history of respiratory tract infection or recent clinically significant change in pulmonary status
* Has a history of chronic bronchitis
* Is currently taking an angiotensin converting enzyme inhibitor (ACEI), or has used an ACEI within 3 months of Screening
* Has an estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m\^2 at Screening OR an eGFR ≥30 mL/min/1.73 m\^2 and \<50 mL/min/1.73 m\^2 at Screening with unstable renal function
* Has a history of malignancy ≤5 years
* Is a user of recreational or illicit drugs or has had a recent history of drug or alcohol abuse or dependence
* Has a history of anaphylaxis or cutaneous adverse drug reaction (with or without systemic symptoms) to sulfonamide antibiotics or other sulfonamide-containing drugs
* Has a known allergy/sensitivity or contraindication to gefapixant
* Has donated or lost ≥1 unit of blood within 8 weeks prior to the first dose of gefapixant
* Has previously received gefapixant
* Currently participating in or has participated in an interventional clinical study within 30 days of screening

Primary outcomes:
measure: Model-Based Geometric Mean Ratio (GMR) of 24-Hour Coughs Per Hour at Week 24/Baseline
timeFrame: Baseline, Week 24
measure: Number of Participants Who Experienced At Least One Adverse Event (AE) During Treatment and Follow-up
timeFrame: Up to 54 Weeks
measure: Number of Participants Who Discontinued a Study Drug Due to an AE
timeFrame: Up to 52 weeks
Secondary outcomes:
measure: Model-Based GMR of Awake Coughs Per Hour at Week 24/Baseline
timeFrame: Baseline, Week 24
measure: Percentage of Participants With a ≥1.3 Point Change From Baseline in the Leicester Questionnaire (LCQ) Total Score at Week 24
timeFrame: Baseline, Week 24
measure: Percentage of Participants With a ≤-30% Change From Baseline in 24-hour Coughs Per Hour at Week 24
timeFrame: Baseline, Week 24
measure: Percentage of Participants With ≤-1.3 Point Change From Baseline of Mean Weekly Cough Severity Diary (CSD) Total Score at Week 24
timeFrame: Baseline, Week 24
measure: Percentage of Participants With ≤-2.7 Point Change From Baseline of Mean Weekly CSD Total Score at Week 24
timeFrame: Baseline, Week 24
measure: Percentage of Participants With a ≤-30 Millimeter (mm) Change From Baseline in Cough Severity Visual Analog Scale (VAS) Score at Week 24
timeFrame: Baseline, Week 24
Other outcomes:
Locations:
city: Peoria
country: United States
facility: Phoenix Medical Group ( Site 0022)
state: Arizona
city: Phoenix
country: United States
facility: Pulmonary Associates, PA ( Site 0063)
state: Arizona
city: Tempe
country: United States
facility: Clinical Research Consortium ( Site 0088)
state: Arizona
city: San Jose
country: United States
facility: Allergy & Asthma Associates of SCV Research Center ( Site 0064)
state: California
city: Sweetwater
country: United States
facility: Lenus Research & Medical Group Llc ( Site 0075)
state: Florida
city: Stockbridge
country: United States
facility: Atlanta Allergy & Asthma Clinic PA ( Site 0029)
state: Georgia
city: Chicago
country: United States
facility: Rush University Medical Center ( Site 0103)
state: Illinois
city: Flossmoor
country: United States
facility: Healthcare Research Network LLC ( Site 0093)
state: Illinois
city: Fort Mitchell
country: United States
facility: Abraham Research, PLLC ( Site 0107)
state: Kentucky
city: Bangor
country: United States
facility: Paul A. Shapero, MD ( Site 0104)
state: Maine
city: Bethesda
country: United States
facility: Bethesda Allergy Asthma and Research Center LLC ( Site 0019)
state: Maryland
city: Ypsilanti
country: United States
facility: Respiratory Medicine Research Institute of Michigan, PLC ( Site 0034)
state: Michigan
city: Edina
country: United States
facility: Minnesota Lung Center ( Site 0108)
state: Minnesota
city: Rochester
country: United States
facility: Mayo Clinic - Rochester ( Site 0006)
state: Minnesota
city: Woodbury
country: United States
facility: Minnesota Lung Center ( Site 0041)
state: Minnesota
city: Chesterfield
country: United States
facility: The Lung Research Center ( Site 0072)
state: Missouri
city: Columbia
country: United States
facility: University of Missouri ENT & Allergy Center ( Site 0066)
state: Missouri
city: Omaha
country: United States
facility: CHI Health Creighton University Medical Center ( Site 0024)
state: Nebraska
city: Las Vegas
country: United States
facility: Clinical Research Consortium ( Site 0050)
state: Nevada
city: Ocean City
country: United States
facility: Atlantic Research Center LLC ( Site 0012)
state: New Jersey
city: Albuquerque
country: United States
facility: Albuquerque Clinical Trials ( Site 0039)
state: New Mexico
city: Bronx
country: United States
facility: Montefiore Medical Center ( Site 0098)
state: New York
city: Raleigh
country: United States
facility: Wake Research Associates, LLC ( Site 0058)
state: North Carolina
city: Columbus
country: United States
facility: Remington-Davis, Inc. ( Site 0082)
state: Ohio
city: Medford
country: United States
facility: Clinical Research Institute of Southern Oregon, PC ( Site 0099)
state: Oregon
city: Portland
country: United States
facility: Allergy Associates Research Center ( Site 0026)
state: Oregon
city: Warwick
country: United States
facility: AAPRI Clinical Research Institute ( Site 0001)
state: Rhode Island
city: Charleston
country: United States
facility: Lowcountry Lung & Critical Care, PA ( Site 0045)
state: South Carolina
city: Greenville
country: United States
facility: Allergic Disease and Asthma Center ( Site 0043)
state: South Carolina
city: Rock Hill
country: United States
facility: Clinical Research of Rock Hill ( Site 0079)
state: South Carolina
city: Richmond
country: United States
facility: Clinical Research Partners, LLC. ( Site 0080)
state: Virginia
city: Bellingham
country: United States
facility: Bellingham Asthma & Allergy ( Site 0076)
state: Washington
city: Spokane
country: United States
facility: Marycliff Clinical Research ( Site 0062)
state: Washington
city: Tacoma
country: United States
facility: Multicare Health System ( Site 0018)
state: Washington
city: Maroubra
country: Australia
facility: Australian Clinical Research Network ( Site 0201)
state: New South Wales
city: Sydney
country: Australia
facility: Holdsworth House Medical Practice ( Site 0206)
state: New South Wales
city: Adelaide
country: Australia
facility: Royal Adelaide Hospital [Adelaide, Australia] ( Site 0214)
state: South Australia
city: Murdoch
country: Australia
facility: Trialswest ( Site 0208)
city: Hamilton
country: Canada
facility: Hamilton Medical Research Group ( Site 0510)
state: Ontario
city: Montreal
country: Canada
facility: Recherche GCP Research ( Site 0500)
state: Quebec
city: Sherbrooke
country: Canada
facility: Q & T Research Sherbrooke Inc. ( Site 0512)
state: Quebec
city: St-Charles-Borromee
country: Canada
facility: Clinique de Pneumologie et du Sommeil de Lanaudiere- CPSL ( Site 0516)
state: Quebec
city: Trois-Rivieres
country: Canada
facility: CIC Mauricie Inc. ( Site 0503)
state: Quebec
city: Victoriaville
country: Canada
facility: Diex Recherche Victoriaville Inc. ( Site 0514)
state: Quebec
city: Quebec
country: Canada
facility: Diex Recherche Quebec Inc ( Site 0515)
city: Quebec
country: Canada
facility: Clinique Specialisee en Allergie de la Capitale - CSAC ( Site 0504)
city: Fuzhou
country: China
facility: The First Affiliated Hospital of Fujian Medical University ( Site 5017)
state: Fujian
city: Guangzhou
country: China
facility: The First Affiliated Hospital of Guangzhou Medical University ( Site 5000)
state: Guangdong
city: Hohhot
country: China
facility: Inner Mongolia Autonomous Region Hospital ( Site 5018)
state: Inner Mongolia
city: Nanchang
country: China
facility: The First Affiliated Hospital of Nanchang University ( Site 5012)
state: Jiangxi
city: Shenyang
country: China
facility: ShengJing Hospital of China Medical University ( Site 5024)
state: Liaoning
city: Shanghai
country: China
facility: Shanghai General Hospital ( Site 5010)
state: Shanghai
city: Hangzhou
country: China
facility: The First Affiliated Hospital of Zhejiang University ( Site 5014)
state: Zhejiang
city: Beijing
country: China
facility: Peking University Third Hospital ( Site 5005)
city: Medellin
country: Colombia
facility: Fundacion Centro de Investigacion Clinica CIC ( Site 0603)
state: Antioquia
city: Medellin
country: Colombia
facility: Hospital Pablo Tobon Uribe ( Site 0600)
state: Antioquia
city: Medellin
country: Colombia
facility: Universidad Pontificia Bolivariana - Clinica Universitaria Bolivariana ( Site 0602)
state: Antioquia
city: Bogota
country: Colombia
facility: Neumo Investigaciones SAS ( Site 0622)
state: Cundinamarca
city: Bogota
country: Colombia
facility: Centro Especializado en Enfermedades Pulmonares. ( Site 0620)
state: Cundinamarca
city: Cali
country: Colombia
facility: Fundacion Valle del Lili ( Site 0618)
state: Valle Del Cauca
city: Cali
country: Colombia
facility: Centro Medico Imbanaco de Cali S.A ( Site 0619)
state: Valle Del Cauca
city: Bogota
country: Colombia
facility: MedPlus Medicina Prepagada S.A. ( Site 0612)
city: Bucaramanga
country: Colombia
facility: Instituto Neumologico del Oriente S.A. ( Site 0649)
city: Medellin
country: Colombia
facility: Inst. Prestadora de Servicios de Salud Universidad Antioquia ( Site 0621)
city: Brandys nad Labem
country: Czechia
facility: MUDr. I. Cierna Peterova s.r.o. ( Site 0707)
city: Jindrichuv Hradec III
country: Czechia
facility: MediTrial s.r.o ( Site 0702)
city: Karlovy Vary
country: Czechia
facility: Ordinace Pneumologie a diagnostiky Plicnich funkci ( Site 0705)
city: Novy Bor
country: Czechia
facility: PNEUMO-NB s.r.o. ( Site 0710)
city: Tabor
country: Czechia
facility: Nemocnice Tabor a.s. ( Site 0703)
city: Herlev
country: Denmark
facility: Herlev Hospital ( Site 0803)
city: Kobenhavn NV
country: Denmark
facility: Bispebjerg Hospital ( Site 0804)
city: Berlin
country: Germany
facility: Aerztezentrum Axel Springer Passage ( Site 1009)
city: Berlin
country: Germany
facility: Atemwegszentrum Neukoeln ( Site 1003)
city: Frankfurt
country: Germany
facility: Gemeinschaftspraxis Zentrum ( Site 1005)
city: Hannover
country: Germany
facility: Pneumologicum im Suedstadtforum ( Site 1004)
city: Leipzig
country: Germany
facility: Pneumologenzentrum ( Site 1006)
city: Neu-Isenburg
country: Germany
facility: Ballenberger Freytag Wenisch Institut fuer klinische Forschung GmbH ( Site 1011)
city: Ulm
country: Germany
facility: PneumoConsult Ulm ( Site 1008)
city: Guatemala
country: Guatemala
facility: Clinipharm ( Site 2902)
city: Guatemala
country: Guatemala
facility: Celan SA ( Site 2900)
city: Guatemala
country: Guatemala
facility: Consultorio Privado Dr. Jeremias Guerra ( Site 2909)
city: Guatemala
country: Guatemala
facility: Clinica Medica Especializada en Neumologia ( Site 2901)
city: Guatemala
country: Guatemala
facility: Clinica Privada Dr. Jose Francisco Flores Lopez ( Site 2903)
city: Balassagyarmat
country: Hungary
facility: Dr Kenessey Albert Korhaz-Rendelointezet ( Site 1200)
city: Budapest
country: Hungary
facility: Synexus Magyarorszag Kft. ( Site 1208)
city: Godollo
country: Hungary
facility: Erzsebet Gondozohaz ( Site 1207)
city: Gyula
country: Hungary
facility: Synexus Magyarorszag Kft. ( Site 1210)
city: Kapuvar
country: Hungary
facility: Lumniczer Sandor Korhaz es Rendelointezet ( Site 1212)
city: Miskolc
country: Hungary
facility: CRU Hungary KFT ( Site 1205)
city: Pecs
country: Hungary
facility: Da Vinci Private Clinic - Da Vinci Maganklinika ( Site 1201)
city: Puspokladany
country: Hungary
facility: Puspokladanyi Egeszsegugyi Szolgaltato Nonprofit Kft ( Site 1203)
city: Rehovot
country: Israel
facility: Kaplan Medical Center ( Site 1300)
city: Firenze
country: Italy
facility: Azienda Ospedaliero Universitaria Careggi ( Site 1400)
city: Alor Star
country: Malaysia
facility: Hospital Sultanah Bahiyah ( Site 1607)
state: Kedah
city: Taiping
country: Malaysia
facility: Hospital Taiping ( Site 1600)
state: Perak
city: George town
country: Malaysia
facility: Hospital Pulau Pinang. ( Site 1606)
state: Pulau Pinang
city: Batu Caves
country: Malaysia
facility: Universiti Teknologi MARA ( Site 1602)
state: Selangor
city: Kuala Lumpur
country: Malaysia
facility: Institut Perubatan Respiratori ( Site 1605)
city: Kuala Lumpur
country: Malaysia
facility: University Malaya Medical Centre ( Site 1601)
city: Auckland
country: New Zealand
facility: Southern Clinical Trials - Waitemata ( Site 0230)
city: Auckland
country: New Zealand
facility: Middlemore Clinical Trials ( Site 0232)
city: Rotorua
country: New Zealand
facility: Lakeland Clinical Trials ( Site 0233)
city: Tauranga
country: New Zealand
facility: P3 Research Ltd. ( Site 0228)
city: San Isidro
country: Peru
facility: Clinica Ricardo Palma ( Site 1802)
state: Lima
city: Cusco
country: Peru
facility: Hospital Nacional Adolfo Guevara Velasco ( Site 1808)
city: Lima
country: Peru
facility: Clinica Internacional ( Site 1801)
city: Lima
country: Peru
facility: Asociacion Civil por la Salud ( Site 1805)
city: Lima
country: Peru
facility: Hospital Nacional Cayetano Heredia [Lima, Peru] ( Site 1806)
city: Lublin
country: Poland
facility: NZOZ CENTRUM ALERGOLOGII ( Site 1909)
state: Lubelskie
city: Katowice
country: Poland
facility: Centrum Medyczne Pratia Katowice ( Site 1917)
state: Slaskie
city: Katowice
country: Poland
facility: Centrum Medyczne Silmedic Sp z o o ( Site 1920)
state: Slaskie
city: Białystok
country: Poland
facility: Centrum Medycyny Oddechowej Mroz Spolka Jawna ( Site 1918)
city: Bychawa
country: Poland
facility: KLIMED ( Site 1902)
city: Katowice
country: Poland
facility: Gyncentrum Clinic Sp. z o.o. ( Site 1908)
city: Krakow
country: Poland
facility: Specjalistyczny osrodek .All-Med. Grazyna Pulka ( Site 1919)
city: Krakow
country: Poland
facility: Centrum Nowoczesnych Terapii Dobry Lekarz ( Site 1924)
city: Lodz
country: Poland
facility: Uniwersytecki Szpital Kliniczny im. Norberta Barlickiego nr 1 ( Site 1921)
city: Ostrowiec Swietokrzyski
country: Poland
facility: Ostrowieckie Centrum Medyczne ( Site 1915)
city: Sochaczew
country: Poland
facility: RCMed ( Site 1912)
city: Swidnik
country: Poland
facility: Lubelskie Centrum Diagnostyczne ( Site 1913)
city: Warszawa
country: Poland
facility: Centrum Medyczne Pratia Warszawa ( Site 1911)
city: Zawadzkie
country: Poland
facility: Centrum Medyczne Lucyna Andrzej Dymek - Zawadzkie ( Site 1923)
city: Brandwag
country: South Africa
facility: Iatros International ( Site 2130)
state: Bloemfontein
city: Morningside
country: South Africa
facility: Rochester Place Medical Centre ( Site 2129)
state: Gauteng
city: Pretoria
country: South Africa
facility: Jongaie Research ( Site 2131)
state: Gauteng
city: Shallcross
country: South Africa
facility: Dr N K Gounden Mediclinic ( Site 2134)
state: Kwazulu Natal
city: Umhlanga Ridge
country: South Africa
facility: Drs Lalloo & Ambaram ( Site 2132)
state: Kwazulu Natal
city: Centurion
country: South Africa
facility: I Engelbrecht Research ( Site 2128)
state: Tswane
city: Cape Town
country: South Africa
facility: UCT Lung Institute - Bateman ( Site 2126)
state: Western Cape
city: Bursa
country: Turkey
facility: Uludag Universitesi Tip Fakultesi ( Site 2621)
state: Gorukle
city: Adana
country: Turkey
facility: Cukurova Universitesi Tıp Fakultesi Balcalı Hastanesi ( Site 2612)
city: Ankara
country: Turkey
facility: Ankara Universitesi Tip Fakultesi Cebeci Hastanesi ( Site 2602)
city: Edirne
country: Turkey
facility: Trakya Universitesi Saglik Arastirma ve Uygulama Merkezi ( Site 2619)
city: Istambul
country: Turkey
facility: Istanbul Universitesi Istanbul Tip Fakultesi Gogus Hastalıklari ABD ( Site 2610)
city: Istambul
country: Turkey
facility: SSK Sureyyapasa Gogus Hastaliklari Hastanesi ( Site 2608)
city: Izmir
country: Turkey
facility: Ege Universitesi Tip Fakultesi Hastanesi ( Site 2603)
city: Izmir
country: Turkey
facility: SBU Dr. Suat Seren Gogus Hast. ve Cer. Egitim ve Arastirma Hast. ( Site 2604)
city: Manisa
country: Turkey
facility: Celal Bayar University Faculty of Medicine ( Site 2614)
city: Chernihiv
country: Ukraine
facility: Chernihiv City hospital N2 ( Site 2801)
city: Chernivtsi
country: Ukraine
facility: CE Chernivtsi state city clinical hospital 3 ( Site 2806)
city: Kherson
country: Ukraine
facility: Kherson City Clinical Hospital n.a. Y.Y. Karabelesh ( Site 2812)
city: Kiev
country: Ukraine
facility: Medical Clinic Blagomed LLC ( Site 2807)
city: Kyiv
country: Ukraine
facility: Kyiv City Tuberculosis Hospital No. 1 ( Site 2814)
city: Kyiv
country: Ukraine
facility: Medical Association Medbud of the PJSC Kyivmiskbud ( Site 2803)
city: KYiv
country: Ukraine
facility: SE Road Clinical Hospital 2 of Kyiv station ( Site 2809)
city: Kyiv
country: Ukraine
facility: Institute of Otolaryngology n. a. Prof. A. I. Kolomiychenko ( Site 2833)
city: Kyiv
country: Ukraine
facility: F.G.Yanovskyy Institute of Phthisiology and Pulmonology ( Site 2804)
city: Kyiv
country: Ukraine
facility: F.G.Yanovskyy Institute of Phthisiology and Pulmonology ( Site 2830)
city: Lutsk
country: Ukraine
facility: Volyn Regional Clinical Hospital ( Site 2829)
city: Poltava
country: Ukraine
facility: Poltava City Clinical Hospital 1 ( Site 2808)
city: Vinnytsia
country: Ukraine
facility: Vinnytsia Regional Clinical Hospital n.a. M.I. Pyrogov ( Site 2819)
city: Zaporizhzhia
country: Ukraine
facility: MI Zaporizhzhia City Multispecialty Clinical Hospital 9 ( Site 2811)
city: Zhytomyr
country: Ukraine
facility: Zhytomyr Central City Hospital #1 ( Site 2828)
city: Cottingham
country: United Kingdom
facility: Hull & East Yorkshire NHS Trust. Castle Hill Hospital ( Site 2704)
state: East Yorkshire
city: Birmingham
country: United Kingdom
facility: Synexus Midlands Clinical Research Centre Ltd ( Site 2719)
state: Edgbaston
city: Romford
country: United Kingdom
facility: Medinova East London Dedicated Research Centre ( Site 2715)
state: Essex
city: Sidcup
country: United Kingdom
facility: Medinova South London Dedicated Research Centre ( Site 2714)
state: Kent
city: Northwood
country: United Kingdom
facility: Medinova North London Dedicated Research Centre ( Site 2716)
state: Middlesex
city: Corby
country: United Kingdom
facility: Medinova Lakeside Dedicated Research Centre ( Site 2710)
state: Northamptonshire
city: Kenilworth
country: United Kingdom
facility: Medinova Warwickshire Dedicated Research Centre ( Site 2717)
state: Warwickshire
city: Belfast
country: United Kingdom
facility: Belfast City Hospital ( Site 2705)
city: Glasgow
country: United Kingdom
facility: Synexus Scotland Clinical Research Centre ( Site 2721)
city: Liverpool
country: United Kingdom
facility: Synexus Merseyside Clinical Research Centre ( Site 2720)
city: Llanelli
country: United Kingdom
facility: Prince Phillip Hospital ( Site 2722)
city: London
country: United Kingdom
facility: 1Kings College Hospital ( Site 2702)
city: Manchester
country: United Kingdom
facility: Synexus Manchester Clinical Research Centre ( Site 2718)
city: Manchester
country: United Kingdom
facility: Wythenshawe Hospital ( Site 2700)
city: North Shields
country: United Kingdom
facility: North Tyneside General Hospital ( Site 2707)
city: Rothwell
country: United Kingdom
facility: Rothwell Medical Centre ( Site 2712)
city: Taunton
country: United Kingdom
facility: Taunton and Somerset Hospital ( Site 2723)
city: Yate
country: United Kingdom
facility: West Walk Surgery ( Site 2711)
Study officials:
affiliation: Merck Sharp & Dohme LLC
name: Medical Director
role: STUDY_DIRECTOR
References:
citation: Dicpinigaitis PV, Birring SS, Blaiss M, McGarvey LP, Morice AH, Pavord ID, Satia I, Smith JA, La Rosa C, Li Q, Nguyen AM, Schelfhout J, Tzontcheva A, Muccino D. Demographic, clinical, and patient-reported outcome data from 2 global, phase 3 trials of chronic cough. Ann Allergy Asthma Immunol. 2023 Jan;130(1):60-66. doi: 10.1016/j.anai.2022.05.003. Epub 2022 May 13.
citation: McGarvey LP, Birring SS, Morice AH, Dicpinigaitis PV, Pavord ID, Schelfhout J, Nguyen AM, Li Q, Tzontcheva A, Iskold B, Green SA, Rosa C, Muccino DR, Smith JA; COUGH-1 and COUGH-2 Investigators. Efficacy and safety of gefapixant, a P2X3 receptor antagonist, in refractory chronic cough and unexplained chronic cough (COUGH-1 and COUGH-2): results from two double-blind, randomised, parallel-group, placebo-controlled, phase 3 trials. Lancet. 2022 Mar 5;399(10328):909-923. doi: 10.1016/S0140-6736(21)02348-5.