Lung Function Outcomes Following Removal of Airway Mucus Plugs in Patients With Asthma (FOCUS) (FOCUS)

January 9, 2026 updated by: University of California, San Francisco

Lung Function Outcomes Following Removal of Airway Mucus Plugs in Patients With Asthma

This is a single-center study that will evaluate the safety and tolerability of removal of mucus plugs by bronchoscopy in patients with asthma. This protocol will also plan for the analysis of the features of the mucus plugs removed.

Study Overview

Status

Withdrawn

Conditions

Intervention / Treatment

Detailed Description

The investigators' research shows that a large subgroup of asthma patients have mucus plugs, and quantification of these plugs using a bronchopulmonary segment-based scoring system reveals a strong negative correlation between the CT (Computed Tomography) mucus plug score and FEV1 (Forced Expiratory Volume at 1 second). The FOCUS study is a single-center study that has the overarching goal to explore the biology of airway mucus plugs in asthma.

Through the FOCUS study, the investigators will initially explore the safety and tolerability of bronchoscopic removal of airway mucus plugs in patients with asthma and mucus plugs. They will then evaluate potential improvements in lung function outcomes in a dose-dependent manner (i.e., by removing mucus plugs from one lung vs both lungs). A secondary objective of the FOCUS study is to perform detailed cellular and molecular analyses of mucus and epithelial cells from airways impacted with mucus. With these biospecimens, the investigators intend to extend their preliminary findings that mucus plugged airways are characterized by intense type 2 inflammation, determine the mechanisms of epithelial and immune cell reprogramming, as well as how cellular reprogramming affects the promotion and persistence of type 2 airway inflammation.

Study Type

Interventional

Phase

  • Not Applicable

Contacts and Locations

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

Study Locations

  • United States
    • California
      • San Francisco, California, United States, 94143
        • UCSF Airway Clinical Research Center

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

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Protocol A:

Inclusion Criteria:

  • Males or females between the ages 18 to 70 at the time of visit 1.
  • Clinical history of asthma per patient report or medical record.
  • Pre-bronchodilator FEV1 < 80% predicted and ≥ 35% predicted
  • CT mucus plug score > 5.
  • Written informed consent obtained from subject and ability for subject to comply with the requirements of the study.

Exclusion Criteria:

  • Smoking of tobacco or other recreational inhalants in the last month and/or >10 pack-year smoking history.
  • History of other pulmonary disorders including cystic fibrosis and COPD (Chronic Obstructive Pulmonary Disease).
  • History of unstable cardiovascular disease.
  • BMI > 45
  • Current use of anticoagulant medications.
  • Upper Respiratory Infection (URI) within the previous 6 weeks
  • Currently pregnant and/or unwillingness to practice medically acceptable birth control or complete abstinence during the study
  • History of COVID-19 (coronavirus disease) in the past 6 months.

Protocol B:

Inclusion Criteria:

  • Males or females between the ages 18 to 80 at the time of visit 1.
  • Undergoing clinically indicated bronchoscopy for removal of mucus plugs.
  • Clinical history of airway disease (including asthma, COPD and bronchiectasis) per patient report or medical record.
  • Written informed consent obtained from subject.

Exclusion Criteria:

  • Upper Respiratory Infection (URI) in the past 30 days.
  • History of COVID-19 in the past 30 days.
  • Currently pregnant during the study.

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Therapeutic bronchoscopy for removal of mucus plugs
Protocol A: This protocol will study 10 patients with asthma who have CT (Computed Tomography) evidence of mucus plugs in their airways. Screening data will be reviewed to determine participant eligibility. Participants who meet all eligibility criteria will participate in a bronchoscopy done on one lung for the first 5 participants, and if single lung mucus removal is well tolerated then we will perform bronchoscopies on both lungs for the next 5 participants.
Procedure: Therapeutic bronchoscopy for removal of mucus plugs
Research participants that meet the study inclusion criteria will undergo a research bronchoscopy to remove airway mucus plugs from 1 lung for the first 5 participants, and, if single lung mucus removal is well tolerated, on both lungs for the next 5 participants.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in FEV1 (Forced Expiratory Volume in the 1st second of Forced Expiration)
Time Frame: 1 week after and six months after research bronchoscopy.
We will assess change from baseline FEV1 one week after and six months after removal of mucus plugs by bronchoscopy.
1 week after and six months after research bronchoscopy.
Incidence of Treatment-Emergent Adverse Events
Time Frame: Up to 1 week after the research bronchoscopy procedure.
We will monitor the safety and tolerability of mucus plug removal by bronchoscopy by tracking the number of participants with treatment-related adverse events.
Up to 1 week after the research bronchoscopy procedure.

Collaborators and Investigators

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

Sponsor

University of California, San Francisco

Collaborators

National Heart, Lung, and Blood Institute (NHLBI)

Investigators

  • Principal Investigator: John Fahy, MD, MS, Professor of Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

January 26, 2022

Primary Completion (Actual)

March 25, 2025

Study Completion (Actual)

March 25, 2025

Study Registration Dates

First Submitted

January 29, 2022

First Submitted That Met QC Criteria

February 17, 2023

First Posted (Actual)

March 1, 2023

Study Record Updates

Last Update Posted (Actual)

January 13, 2026

Last Update Submitted That Met QC Criteria

January 9, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 21-33420
  • 2P01HL107202-06A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

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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