A 24-Week Study of the Efficacy and Safety of BLU-5937 in Adults With Refractory Chronic Cough - China Extension (CALM-2)

June 10, 2026 updated by: GlaxoSmithKline

A Phase 3, 24-Week, Randomized, Double-Blind, Placebo-Controlled, Parallel-Arm Efficacy and Safety Study With Open-label Extension of BLU-5937 in Adult Participants With Refractory Chronic Cough Including Unexplained Chronic Cough (CALM-2) - China Extension

This is a randomized, double-blind, placebo-controlled, parallel-arm, Phase 3 study of BLU-5937 in participants with Refractory Chronic Cough (RCC).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The primary efficacy objective is to assess the effect of BLU-5937 on 24-hour cough frequency in adults with refractory chronic cough (including unexplained chronic cough) at 24 weeks.

Study Type

Interventional

Enrollment (Estimated)

75

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • China
      • Beijing, China, 100730
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Kewu Huang
      • Changsha, China, 410008
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • pinhua Pan
        • Contact:
        • Contact:
      • Chengdu, China, 610041
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Gang Wang
        • Contact:
        • Contact:
      • Chengdu, China, 610021
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Hao yan
      • Chongqing, China, 408099
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Qianli Ma
      • Dongguan, China, 523326
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Lei Wu
        • Contact:
        • Contact:
      • Ganzhou, China, 341000
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • tang xiaoyuan
      • Guangzhou, China, 510000
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Lai Kefang
      • Guangzhou, China, 510260
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • jun Yang
        • Contact:
        • Contact:
      • Guilin, China, 541002
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Feng Gao
      • Hangzhou, China, 310003
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Jianying Zhou
        • Contact:
        • Contact:
      • Hefei, China, 230001
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Xiaowen Hu
        • Contact:
        • Contact:
      • Hefei, China, 230022
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Xiaoyun Fan
      • Hohhot, China, 010017
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Maoye Xu
      • Huizhou, China, 516000
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Feng Wu
        • Contact:
        • Contact:
      • Huizhou, China, 516001
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • changqing lin
      • Jiangsu, China, 221004
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Bi Chen
        • Contact:
        • Contact:
      • Jinan, China, 250021
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Yi Liu
        • Contact:
        • Contact:
      • Kunming, China, 650032
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Jianqing Zhang
      • Liuzhou, China
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Jian Huang
      • Meizhou, China, 514700
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • du yanjia
      • Nanchang, China, 330038
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Zuke Xiao
        • Contact:
        • Contact:
      • Pingxiang, China, 337055
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Limin Dong
      • Shanghai, China, 200032
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Meiling Jin
        • Contact:
        • Contact:
      • Shanghai, China, 200065
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Xianghuai XU
      • Shanghai, China, 200080
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Min Zhang
      • Shenyang, China, 110004
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Li Zhao
        • Contact:
        • Contact:
      • Shenzhen, China, 518053
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Lei Rong
        • Contact:
        • Contact:
      • Taizhou, China, 317000
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • youzu xu
      • Weifang, China
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Bo Liu
      • Wuxi, China, 214023
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Tao Bian
        • Contact:
        • Contact:
      • Xiamen, China, 361004
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Yihua Lin
      • Yangzhou, China, 225001
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Feng Wu
        • Contact:
        • Contact:
      • Yinchuan, China
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • jia hou
      • Zhanjiang, China, 524045
        • Recruiting
        • GSK Investigational Site
        • Principal Investigator:
          • Zhennan Yi
        • Contact:
        • Contact:
      • Zhengzhou, China, 450052
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Zhe Cheng
      • Ürümqi, China, 830001
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Xuemei Wei
    • Sichuan
      • Leshan, Sichuan, China, 614003
        • Recruiting
        • GSK Investigational Site
        • Contact:
        • Contact:
        • Principal Investigator:
          • Hailong Wei

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Capable of giving signed informed consent

  • Refractory chronic cough (including unexplained chronic cough) for at least one year

    • Women of child-bearing potential must use a highly effective contraception method during the study and for at least 14 days after the last dose

Exclusion Criteria:

  • Current smoker/vaper (all forms of smoking and inhaled substances, including, cannabis/tobacco smoke and nicotine vapors) or individuals who have given up smoking within the past 6 months, or those with >20 pack-year smoking history
  • Diagnosis of chronic obstructive pulmonary disease, bronchiectasis, chronic bronchitis, cystic fibrosis, pulmonary sarcoidosis, idiopathic pulmonary fibrosis, uncontrolled asthma, or other significant or progressive airway/respiratory disorder that might affect cough based on clinician assessment
  • Respiratory tract infection within 4 weeks before screening
  • Laboratory confirmed Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection at screening
  • History of malignancy in the last 5 years
  • History of alcohol or drug abuse within the last 3 years
  • Has a positive serologic test for human immunodeficiency virus (HIV), hepatitis B virus surface antigen, or hepatitis C virus.
  • Previous participation in a BLU-5937 trial

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: BLU-5937 25 mg
BLU-5937 oral dose 25 mg twice a day.
Drug: BLU-5937
Oral administration of BLU-5937 Tablets.
Other Names:
  • Camlipixant
Experimental: BLU-5937 50 mg
BLU-5937 oral dose 50 mg twice a day.
Drug: BLU-5937
Oral administration of BLU-5937 Tablets.
Other Names:
  • Camlipixant
Placebo Comparator: Placebo
Matching Placebo for BLU-5937 oral dose twice a day.
Drug: Placebo
Oral administration of matching placebo for BLU-5937 Tablets.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
24-Hour Cough Frequency
Time Frame: Week 24
Assessed using an ambulatory cough monitor
Week 24
Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs) up to Week 24
Time Frame: Up to Week 24
An AE is any untoward medical occurrence in a clinical study participant administered a medicinal product and which does not necessarily have a causal relationship with that product. An SAE is defined as any untoward medical occurrence that, at any dose, meets one or more of the criteria listed: results in death, is life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect in the offspring of a study participant; or other situations as per the medical or scientific judgment of the Investigator.
Up to Week 24
Number of Participants with Adverse Events of Medical Interest (AEMIs) up to Week 24
Time Frame: Up to Week 24
An AEMI is an event of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring is appropriate. The following are AEMIs for this study: taste disturbance, oral hypoesthesia, oral paresthesia, and new or worsening findings of the cornea.
Up to Week 24
Number of Participants with Study Treatment Discontinuation due to AEs and SAEs up to Week 24
Time Frame: Up to Week 24
An AE is any untoward medical occurrence in a clinical study participant administered a medicinal product and which does not necessarily have a causal relationship with that product. An SAE is defined as any untoward medical occurrence that, at any dose, meets one or more of the criteria listed: results in death, is life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect in the offspring of a study participant; or other situations as per the medical or scientific judgment of the Investigator.
Up to Week 24
Number of Participants with AEs and SAEs Leading to Study Withdrawal up to Week 24
Time Frame: Up to Week 24
An AE is any untoward medical occurrence in a clinical study participant administered a medicinal product and which does not necessarily have a causal relationship with that product. An SAE is defined as any untoward medical occurrence that, at any dose, meets one or more of the criteria listed: results in death, is life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect in the offspring of a study participant; or other situations as per the medical or scientific judgment of the Investigator.
Up to Week 24
Change from Baseline in Vital Signs: Systolic and Diastolic Blood Pressure (millimeters of mercury [mm Hg]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Vital Sign: Pulse (beats per minute) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Vital Sign: Respiratory Rate (breaths per minute) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Vital Sign: Body Temperature (degrees Celsius) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Vital Sign: Weight (kilograms [kg]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Male Reproductive Hormone: Total Testosterone (nanomoles per liter [nmol/L]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Male Reproductive Hormones: Follicle-Stimulating Hormone [FSH] and Luteinizing Hormone [LH] (international units per liter [IU/L]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Male Reproductive Hormone: Inhibin B (nanograms per liter [ng/L]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Hematology Parameter: Red Blood Cell (RBC) Count (10^12 cells per liter) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Hematology Parameters: Hemoglobin and Mean Corpuscular Hemoglobin Concentration (MCHC) (grams per liter [g/L]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Hematology Parameter: Hematocrit (percentage) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Hematology Parameter: Mean Corpuscular Volume (MCV) (femtoliters [fL]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Hematology Parameter: Mean Corpuscular Hemoglobin (MCH) (picograms per cell [pg/cell]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Hematology Parameter: Red Cell Distribution Width (RDW) (percentage) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Hematology Parameters: White Blood Cell (WBC) Count (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) and Platelet Count (10^9 cells per liter) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Clinical Chemistry Parameters: Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), and Gamma-Glutamyl Transferase (GGT) (units per liter [U/L]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Clinical Chemistry Parameters: Alkaline Phosphatase (ALP) and Creatine Kinase (CK) (international units per liter [IU/L]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Clinical Chemistry Parameters: Total Bilirubin, Direct and Indirect Bilirubin, and Creatinine (micromoles per liter) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Clinical Chemistry Parameters: Sodium, Potassium, Chloride, Calcium, Magnesium, Bicarbonate, Glucose, and Blood Urea Nitrogen (BUN) (millimoles per liter [mmol/L]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Clinical Chemistry Parameters: Protein and Albumin (grams per liter [g/L]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Clinical Chemistry Parameter: Estimated Glomerular Filtration Rate (eGFR) (milliliters per minute per 1.73 meters squared [mL/min/1.73 m^2]) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Clinical Chemistry Parameters: Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT) (seconds) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Electrocardiogram (ECG) Value: Heart Rate (beats per minute) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in ECG Value: PR Interval, QT Interval, RR Interval, QRS Interval, and Corrected QT Interval Using Fridericia's Formula (QTcF) (milliseconds) at Week 24
Time Frame: Baseline, Week 24
Baseline, Week 24

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from Baseline in the Leicester Cough Questionnaire (LCQ) Total Score at Week 24
Time Frame: Baseline, Week 24
The LCQ is a patient-reported quality of life (QOL) measure of chronic cough. The questionnaire consists of 19 items to which the patient responds on a 7-point Likert response scale (from 1 to 7). Each item assesses symptoms during cough and the impact of cough on 3 domains: physical, psychological, and social. Domain scores range from 1-7, and the total score ranges from 3 - 21; a higher score indicates a better quality of life.
Baseline, Week 24
Change from Baseline in Cough Severity Visual Analogue Scale at Week 24
Time Frame: Baseline, Week 24
Assessed by Cough Severity Visual Analogue Scale [VAS] by the participant on a 100 mm visual analogue scale where higher scores indicate greater severity.
Baseline, Week 24
Percentage of Participants With Greater than or Equal to (>=) 30 mm Reduction From Baseline in Cough Severity Visual Analog Scale at Week 24
Time Frame: Baseline, Week 24
Assessed by Cough Severity Visual Analogue Scale [VAS] by the participant on a 100 mm visual analogue scale where higher scores indicate greater severity.
Baseline, Week 24
Awake Cough Frequency at Week 24
Time Frame: Week 24
Assessed using an ambulatory cough monitor
Week 24
Percentage of Participants With >= 30 percent (%) Reduction From Baseline in 24-Hour Cough Frequency at Week 24
Time Frame: Baseline, Week 24
Assessed using an ambulatory cough monitor
Baseline, Week 24
Percentage of Participants With a >= 1.3-point Increase From Baseline in Leicester Cough Questionnaire (LCQ) Total Score at Week 24
Time Frame: Baseline, Week 24
The LCQ is a patient-reported quality of life (QOL) measure of chronic cough. The questionnaire consists of 19 items to which the patient responds on a 7-point Likert response scale (from 1 to 7). Each item assesses symptoms during cough and the impact of cough on 3 domains: physical, psychological, and social. Domain scores range from 1-7, and the total score ranges from 3 - 21; a higher score indicates a better quality of life.
Baseline, Week 24
Change from Baseline in the Chronic Cough Diary (CCD) Score at Week 24
Time Frame: Baseline, Week 24
The CCD is a participant-completed daily diary used to assess chronic cough. The CCD score ranges from 0 to 16, with a higher score indicating worse symptoms.
Baseline, Week 24
Percentage of Participants with CCD Response at Week 24
Time Frame: Week 24
Percentage of participants with CCD response will be summarized.
Week 24

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

GlaxoSmithKline

Investigators

  • Study Director: GSK Clinical Trials, GlaxoSmithKline

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 21, 2025

Primary Completion (Estimated)

August 27, 2027

Study Completion (Estimated)

June 2, 2028

Study Registration Dates

First Submitted

June 10, 2026

First Submitted That Met QC Criteria

June 10, 2026

First Posted (Actual)

June 16, 2026

Study Record Updates

Last Update Posted (Actual)

June 16, 2026

Last Update Submitted That Met QC Criteria

June 10, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 221851-CHN
  • BUS-P3-02, (Other Identifier: Bellus Health Inc)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk.com/en-gb/innovation/trials/data-transparency/

IPD Sharing Time Frame

Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or asset(s) with development terminated across all indications.

IPD Sharing Access Criteria

Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months, but an extension may be granted, when justified, for up to 6 months.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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