Clinical trial NCT03315000: Effect of Vilanterol on Methacholine Challenge Results
Official title: The Effect of Vilanterol Against Methacholine-induced Bronchoconstriction in Mild Asthmatics
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Asthma
Keywords: methacholine
airway hyperresponsiveness
Lead sponsor: University of Saskatchewan
Sponsor class: OTHER
First posted: 2017-10-19
Enrollment: 17
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: The study will assess the degree of bronchoprotection provided by the ultra long-acting beta2 agonist vilanterol against methacholine-induced bronchoconstriction.

Detailed description: This will be a double-blind, three-way crossover study comparing combination vilanterol+fluticasone with fluticasone monotherapy and a placebo (vilanterol is not available as a monotherapy). The order in which the treatments are given will be randomized and each treatment will be separated by a minimum one-week washout. Fifteen asthmatic participants will be recruited from the local community. Methacholine challenge testing (MCT) with the two-minute tidal breathing protocol will be used to quantify the bronchoprotective effects (if any) of each treatment against methacholine-induced bronchoconstriction.

Each participant will undergo a total of nine methacholine challenges. After a baseline methacholine challenge, the randomized treatment (identity unknown to investigator or participant) will be administered through an Ellipta® (multi-dose dry powder inhaler). Thirty minutes following treatment administration, a second methacholine challenge will be performed. At 24 hours post-treatment, each participant must re-visit the lab for one methacholine challenge. The same process will be followed for each treatment.

Eligibility criteria: Inclusion Criteria:

* men and women aged 18 or older
* stable mild-to-moderate asthma
* baseline methacholine PC20 less than or equal to 8mg/mL
* FEV1 greater than or equal to 65% of predicted

Exclusion Criteria:

* Use of long-acting anticholinergic or long-acting beta2 agonist within 30 days of study
* pregnant or nursing
* diabetes
* hypokalemia
* cardiovascular, prostate, kidney, or urinary retention problems
* lactose-intolerant
* allergy-induced asthma symptoms or upper respiratory tract infection within four weeks of study
* current smokers
* past smokers with smoking history \>10 pack years

Primary outcomes:
measure: Change from baseline methacholine PC20 (bronchoprotection) at 30 min post-treatment
timeFrame: baseline versus 30 min post-treatment
Secondary outcomes:
measure: Change from baseline methacholine PC20 (bronchoprotection) at 24 hours post-treatment
timeFrame: baseline versus 24 hours post-treatment
Other outcomes:
Locations:
city: Saskatoon
country: Canada
facility: Asthma Research Lab - University of Saskatchewan
state: Saskatchewan
Study officials:
affiliation: University of Saskatchewan
name: Don Cockcroft, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Westbury GLM, Blais CM, Davis BE, Cockcroft DW. Bronchoprotective effect of vilanterol against methacholine-induced bronchoconstriction in mild asthmatics: A randomized three-way crossover study. Ann Allergy Asthma Immunol. 2018 Sep;121(3):328-332. doi: 10.1016/j.anai.2018.07.005. Epub 2018 Jul 12.