REVErsing Airway Remodelling With Tezepelumab

Tezepelumab is a human IgG2l monoclonal antibody (mAb) directed against TSLP. Double-blind, randomized controlled trials comparing Tezepelumab treatment against placebo demonstrate net positive benefits in asthma patients. Animal research currently indicates that blocking TSLP can prevent bronchial remodelling in murine models (Chen et al. 2013), but no such observations have been attempted in humans. Within this context, the aim of this protocol is to perform a first randomized controlled trial evaluating how Tezepelumab affects the bronchial morphology (and computed tomographic variables in general) of asthmatic patients. In parallel, the investigators also hope to reproduce clinical benefits and perform a transcriptomic study that will juxtapose changes in genetic expression with changes in bronchial morphology and inflammatory signatures. The general hypothesis is that tezepelumab treatment is capable of at least partially reversing bronchial remodelling as detected on computed-tomographic (CT) scans. The investigators also expect such reversal to occur within a unique physiological repair environment that will be reflected by transcriptomic profiles. The primary objective of this protocol is therefore to compare the change-from-baseline in the average percentage bronchial wall area (%WA = (wall area (mm2)/ (wall area (mm2) + lumen area (mm2)))×100) for patients with asthma and undergoing 6 months of tezepelumab treatment with a similar population treated via placebo. Secondarily, continued treatment effects associated with longer treatment (12 months) or remanence after treatment stopping at 6 months will also be quantified. Study arms will additionally be compared in terms of: * Changes in radiomics (CT-scan data); * Changes in exacerbation rates and lung function; * Changes in serum club cell secretory protein (CCSP); * Changes in nasal single-cell transcriptomic signatures. This study also has an exploratory component designed to characterize the physiological repair environment. In depth radiomic and transcriptomic (including single-cell analyses) profiling will be performed. Finally, the capacity of baseline data to predict the response to tezepelumab will also be explored.