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Clinical Trial of NAC in Asthma (CONA)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02605824
Recruitment Status : Terminated (The study was closed after we determined that this albuterol/NAC regimen may be associated with excessive bronchoconstriction.)
First Posted : November 16, 2015
Results First Posted : August 20, 2019
Last Update Posted : August 20, 2019
Information provided by (Responsible Party):
University of California, San Francisco

Brief Summary:
This study evaluates 20% n-acetylcystine (NAC) in the treatment of moderate-to-severe asthma that is complicated by mucus in the airway, as determined by CT imaging. The study is a crossover design, which means that half the study participants will get 20% NAC in the first 7-day treatment period and placebo in the next 7-day treatment period; and the other half will get placebo in the first 7-day treatment period and 20% NAC in the next 7-day treatment period.

Condition or disease Intervention/treatment Phase
Asthma Drug: n-acetylcystine Drug: 0.9% saline Phase 4

Detailed Description:

n-acetylcystine (NAC) is a mucolytic medication, meaning that it breaks apart mucus. Investigators know that mucus is a factor in severe asthma attacks. However, mucus may be a factor in chronic severe asthma as well. This role has been hard to prove because of difficulty in showing that mucus occludes the lumen in chronic severe disease. Using a novel approach of scoring mucus occlusion, investigators have used CT imaging to uncover that a majority of people with severe asthma have at least one lung segment with a mucus plug and 27% have more than four lung segments with mucus plugs.

Historically, studies of mucolytics, like NAC, have not shown benefit in other obstructive lung diseases, like COPD. However, utilizing CT mucus scores as a biomarker, investigators believe that mucolytic treatment may prove useful for those with significant mucus impaction.

This is a randomized, double-blind, placebo-controlled phase 4 study of 20% NAC in patients with asthma who also have evidence of mucus in their lungs as determined by CT imaging. Investigators hypothesize that by treating asthmatics, chosen based on the presence of mucus in the airways, with a mucolytic like NAC, will result in an improvement of lung function.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 1 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: Clinical Trial of NAC in Asthma
Actual Study Start Date : March 2016
Actual Primary Completion Date : December 2017
Actual Study Completion Date : December 2017

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Asthma

Arm Intervention/treatment
Experimental: 20% n-acetylcystine (NAC)
NAC (trade name: Mucomyst) is manufactured by American Regent. The active drug studied here is 20% NAC delivered via nebulizer three times per day for seven days.
Drug: n-acetylcystine
NAC is a mucolytic drug.
Other Names:
  • Mucomyst
  • NAC
  • acetylcystine

Placebo Comparator: 0.9% saline
Normal saline will be administered as the placebo agent via a nebulizer three times per day for seven days.
Drug: 0.9% saline
Normal saline is a placebo agent.
Other Name: Normal saline

Primary Outcome Measures :
  1. Change in Post-bronchodilator FEV1 (L) [ Time Frame: 7 days ]
    This is a measure of forced expiratory volume measured in one second, following the administration of 4 puffs of albuterol. This outcome will compare the change in post-bronchodilator FEV1 (L) both before and after treatment.

Secondary Outcome Measures :
  1. Change CT Mucus Score [ Time Frame: 7 days ]
    The CT Mucus Score describes the number of segments of the lungs that are impacted by mucus. This outcome will compare the change in CT mucus score both at baseline and following each treatment period.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Able to perform reproducible spirometry according to ATS criteria
  • Clinical history consistent with moderate to severe asthma for 1 year or greater.
  • Post-bronchodilator FEV1 <90% of predicted
  • Prescription and daily use of inhaled corticosteroid (ICS) equivalent to 240mcg of beclomethasone or greater and a second asthma controller therapy.
  • CT mucus score >3 (determined during the initial screening process, provided the prior two conditions are met)
  • Written informed consent obtained from participant and ability for participant to comply with the requirements of the study.

Exclusion Criteria:

  • Pregnant, breastfeeding, or unwilling to practice birth control during participation in the study.
  • Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data.
  • History of intolerance to study medications.
  • Current use of carbamazepine
  • Angina which includes a treatment plan with PRN nitroglycerin or nitrites
  • Smoking of tobacco or other recreational inhalants in last year and/or >10 pack-year smoking history
  • Current participation in an investigational drug trial Concurrent Medications

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02605824

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United States, California
UCSF Airway Clinical Research Center
San Francisco, California, United States, 94143
Sponsors and Collaborators
University of California, San Francisco
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Principal Investigator: John V Fahy, MD, MSc University of California, San Francisco
  Study Documents (Full-Text)

Documents provided by University of California, San Francisco:
Additional Information:
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Responsible Party: University of California, San Francisco Identifier: NCT02605824    
Other Study ID Numbers: 15-17919
First Posted: November 16, 2015    Key Record Dates
Results First Posted: August 20, 2019
Last Update Posted: August 20, 2019
Last Verified: July 2019

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Lung Diseases
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases
Antiviral Agents
Anti-Infective Agents
Respiratory System Agents
Free Radical Scavengers
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs