Tezepelumab on Airway Structure and Function in Patients With Uncontrolled Moderate-to-severe Asthma

Last updated: January 5, 2026
Sponsor: McMaster University
Overall Status: Completed

Phase

3

Condition

Asthma

Treatment

Tezepelumab

Placebo

Clinical Study ID

NCT05280418
ESR-20-210000
  • Ages > 18
  • All Genders

Study Summary

In adult patients with uncontrolled moderate-to-severe asthma, blocking TSLP with tezepelumab will improve ventilation heterogeneity (evaluated by hyperpolarized 129Xe MRI), and this will be associated with reduced airway inflammation (evaluated by sputum composition), luminal narrowing and plugging (evaluated by CT).

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • General

  • Able and willing to provide written informed consent.

  • Able and willing to comply with the study protocol.

  • Males and females ≥ 18 years of age.

  • Asthma-related

  • Asthma diagnosed by a respiratory physician ≥12 months prior to study enrolmentbased on the Global Initiative for Asthma (GINA) 2021 guidelines.

  • ACQ ≥1.5 at screening.

  • Methacholine PC20 ≤ 4 mg/mL OR ≥15% decrease in FEV1 during saline inhalationfor sputum induction OR ≥15% improvement in FEV1 after bronchodilator duringthe screening period.

  • Criteria met for moderate or severe asthma defined by GINA 2021 guidelines,i.e. treatment with low, medium or high dose ICS (<250 mcg, 251 - 500 mcg, >500mcg of fluticasone equivalent/day respectively) plus another controller.Patients on prednisone would not be excluded, as long as they meet the rest ofthe inclusion criteria.

  • FeNO >25 ppb OR ≥3% sputum eosinophils (preferred) OR blood eos ≥300/µL duringthe screening period.

  • History of ≥1 exacerbation in the previous year.

Exclusion

Exclusion Criteria:

  • General

-- Participation in any clinical trial of an investigational agent or procedurewithin six months prior to screening or during the study.

  • Medical conditions and treatment history

  • History of anaphylaxis to any previous biologic therapy received.

  • Receipt of live attenuated vaccine within 30 days, receipt of COVID vaccinewithin 28 days, known or suspected COVID infection at the time of enrollment.

  • Acute or chronic parasitic, bacterial, fungal or viral infections thatrequired, or currently requires, hospitalization or antimicrobial treatmentduring the last four weeks.

  • Acute asthma exacerbation event treated with increased doses of oral, or anydose of intramuscular (IM) or intravenous (IV) corticosteroids within six weeksprior to screening.

  • Other relevant pulmonary diseases (e.g. chronic obstructive pulmonary disease,idiopathic pulmonary fibrosis, cystic fibrosis, pulmonary arterialhypertension, tuberculosis) requiring treatment within 12 months prior toscreening.

  • Alcohol or substance abuse within 12 months prior to screening.

  • Current smoker defined as having smoked at least one cigarette (or pipe, cigar, ormarijuana) per day for ≥ 30 days within the three months prior to screening.

  • Ex-smokers with ≥ 10 pack-year smoking history.

  • Pregnancy.

  • Treatment with anti-IgE, anti-IL-4, anti-IL-5, or anti-IL-13 targeted therapycurrently or within three months prior to screening.

  • MRI-related

  • Patient has an implanted mechanically, electrically or magnetically activateddevice or any metal in their body which cannot be removed, including but notlimited to pacemakers, neurostimulators, biostimulators, implanted insulinpumps, aneurysm clips, bioprosthesis, artificial limb, metallic fragment orforeign body, shunt, surgical staples (including clips or metallic suturesand/or ear implants) (at the discretion of the MRI Technologist).

  • In the investigator's opinion, subject suffers from any physical, psychologicalor other condition(s) that might prevent performance of the MRI, such as severeclaustrophobia.

Study Design

Total Participants: 27
Treatment Group(s): 2
Primary Treatment: Tezepelumab
Phase: 3
Study Start date:
November 08, 2022
Estimated Completion Date:
December 17, 2025

Study Description

The luminal obstruction in asthma that contributes to symptoms is due to inflammatory cells (usually eosinophils or neutrophils), mucus, smooth muscle constriction, airway wall thickness, or a combination of the above. This obstruction can be regionally visualized and quantified by computed tomography (CT), and its functional consequence can be assessed at high resolution using inhaled hyperpolarized 129Xe gas magnetic resonance imaging (MRI). Thymic stromal lymphopoietin (TSLP), an epithelial cell derived cytokine that is produced in response to environmental and proinflammatory stimuli, may contribute to all of these features of asthma through its downstream effects on a wide variety of immune (e.g. eosinophils, mast cells, group 2 innate lymphoid cells (ILC2s), Th2 cell, and Th17 cells) and structural cells (e.g. smooth muscle cells, and fibroblasts). Of note, TSLP is believed to upregulate multiple downstream inflammatory pathways, including IL-4, IL-5 and IL-13 signalling. It is also believed to mediate structural mechanisms that contribute to airway remodelling and smooth muscle dysfunction.

The consequence of blocking TSLP with tezepelumab on airway structure and function has not been investigated. This study will use CT to quantify airway wall and lumen structure according to previously described methods. CT images will also be evaluated for intraluminal plugging and a visual mucus score will be generated. Ventilation heterogeneity in asthmatics, the functional consequence of luminal obstruction, can be regionally measured with high temporal and spatial resolution using inhaled hyperpolarized gas MRI. In asthmatics, focal ventilation defects are observed and these have been shown to be spatially related to airway abnormalities and to respond to bronchoconstriction, bronchodilation, and anti-T2 biologics.

Due to the potential effect of tezepelumab on luminal inflammation, smooth muscle dysfunction and mucus hypersecretion, it is believed that MRI-detectable improvements in ventilation heterogeneity will be observed in asthmatics.

Connect with a study center

  • Firestone Institute for Respiratory Health

    Hamilton, Ontario L8N 4A6
    Canada

    Site Not Available

  • Firestone Institute for Respiratory Health

    Hamilton 5969782, Ontario 6093943 L8N 4A6
    Canada

    Site Not Available

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