A Study of Gefapixant (MK-7264) in Adult Participants With Chronic Cough (MK-7264-030)

Chronic Cough Clinical Trial

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)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03449147
• Other study ID #: 7264-030
• Secondary ID: MK-7264-0302017-
• Status: Completed
• Phase: Phase 3
• Start date: March 15, 2018
• Est. completion date: October 30, 2020

Study information

• Verified date: August 2021
• Source: Merck Sharp & Dohme Corp.
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 1317
• Est. completion date: October 30, 2020
• Est. primary completion date: August 20, 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

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

Related Conditions & MeSH terms

• Chronic Cough
• Cough

Intervention

Drug:
• Placebo
Placebo tablet administered orally BID
• Gefapixant 15 mg BID
Gefapixant 15 mg tablet administered orally BID
• Gefapixant 45 mg BID
Gefapixant 45 mg tablet administered orally BID

Locations

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

Sponsors (1)

Lead Sponsor	Collaborator
Merck Sharp & Dohme Corp.

Countries where clinical trial is conducted

United States,  Australia,  Canada,  China,  Colombia,  Czechia,  Denmark,  Germany,  Guatemala,  Hungary,  Israel,  Italy,  Malaysia,  New Zealand,  Peru,  Poland,  South Africa,  Turkey,  Ukraine,  United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Model-Based Geometric Mean Ratio (GMR) of 24-Hour Coughs Per Hour at Week 24/Baseline	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.	Baseline, Week 24
Primary	Number of Participants Who Experienced At Least One Adverse Event (AE) During Treatment and Follow-up	An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.	Up to 54 Weeks
Primary	Number of Participants Who Discontinued a Study Drug Due to an AE	An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention.	Up to 52 weeks
Secondary	Model-Based GMR of Awake Coughs Per Hour at Week 24/Baseline	Awake coughs per hour was defined as the average hourly cough frequency while the participant is awake, based on a 24-hour interval of sound recordings using a digital recording device (cough monitor). ANCOVA model was applied to log-transformed cough data to determine GM of awake coughs per hour at baseline and week 24. The GMR (Week 24 GM awake coughs per hour divided by Baseline GM awake coughs per hour) is reported.	Baseline, Week 24
Secondary	Percentage of Participants With a =1.3 Point Change From Baseline in the Leicester Questionnaire (LCQ) Total Score at Week 24	The 19-item LCQ assessed the impact of chronic cough in three health-related quality of life (HRQoL) domains (physical, social and psychological). The LCQ is calculated as a mean score for each domain ranging from 1 to 7, with a total score ranging from 3 to 21. Higher scores indicate better HRQoL. A clinically meaningful improvement from baseline in HRQoL was defined as =1.3-point increase in the LCQ total score at Week 24. The percentage of participants (logistic regression model-based) with a =1.3-point increase in the LCQ total score at Week 24 is presented.	Baseline, Week 24
Secondary	Percentage of Participants With a =-30% Change From Baseline in 24-hour Coughs Per Hour at Week 24	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 clinically meaningful improvement from baseline is defined as a =-30% change (=30% reduction) in 24-hour coughs per hour at week 24. The percentage of participants (logistic regression model-based) with a = -30% change from baseline in 24-hour coughs per hour at Week 24 (=30% reduction from baseline) is presented.	Baseline, Week 24
Secondary	Percentage of Participants With =-1.3 Point Change From Baseline of Mean Weekly Cough Severity Diary (CSD) Total Score at Week 24	The 7-item CSD was used to record participants' daily cough frequency, cough intensity, and disruption due to cough. Each item was rated on an 11-point scale ranging from 0 (best) to 10 (worst); the total daily CSD score was the sum of these seven item scores (Min=0, Max=70). Mean weekly CSD total score was defined as the average of the mean total daily scores collected during the week prior to each visit. The percentage of participants (logistic regression model-based) with a =-1.3 point change from baseline in CSD at Week 24 (or =1.3 point reduction from baseline) is reported.	Baseline, Week 24
Secondary	Percentage of Participants With =-2.7 Point Change From Baseline of Mean Weekly CSD Total Score at Week 24	The 7-item CSD was used to record participants' daily cough frequency, cough intensity, and disruption due to cough. Each item was rated on an 11-point scale ranging from 0 (best) to 10 (worst); the total daily CSD score was the sum of these seven item scores (Min=0, Max=70). Mean weekly CSD total score was defined as the average of the mean total daily scores collected during the week prior to each visit. The percentage of participants (logistic regression model-based) with a =-2.7 point change from baseline in CSD at Week 24 (or =2.7 point reduction from baseline) is reported.	Baseline, Week 24
Secondary	Percentage of Participants With a =-30 Millimeter (mm) Change From Baseline in Cough Severity Visual Analog Scale (VAS) Score at Week 24	The VAS is a single-item questionnaire with the response on a 100- point scale ranging from 0 ("No Cough") to 100 ("Extremely Severe Cough"). Mean weekly VAS score was defined as the average of the VAS scores collected during the week prior to each visit. The percentage of participants (logistic regression model-based) with a =-30 mm change from baseline in cough severity VAS score at Week 24 is reported.	Baseline, Week 24