The purpose of this study is to determine whether anti-TSLP will decrease airway hyperresponsiveness in patients with asthma already on daily treatment with inhaled corticosteroids. The investigators expect that airway hyperresponsiveness will decrease after treatment with anti-TSLP, and that this happens due to a change in the type of mast cells with in the lungs. Also, the investigators expect a decrease in inflammatory cells and mediators measured in material from the lungs. Half of the participants will receive anti-TSLP (MEDI9929) on top of their regular asthma treatment, while the other half will receive placebo on top of their regular asthma treatment.
The mannitol test is increasingly used by clinicians to diagnose asthma. It has clinical advantages in terms of being feasible in a wide range of settings with the need of a minimum of equipment. Airway hyper responsiveness (AHR) to mannitol correlates with eosinophilic airway inflammation and the degree of asthma control, predicts the risk of exacerbation and response to inhaled steroids. Subjects with asthma and indirect AHR have increased levels of intraepithelial carboxypeptidase A3 (CPA3), a metalloexopeptidase specifically expressed by mast cells, compared to asthmatics without AHR. CPA3 is known to be selectively present in the MCTC phenotype (mast cells containing both tryptase and chymase), and recent studies suggest that increased CPA3 levels also constitutes a marker of a Th2-high/eosinophilic and steroid-responsive asthma. Interestingly, treating mast cell precursors with TSLP increases CPA3 immunostaining, suggesting that TSLP released by e.g. airway epithelium up-regulate a mast cell phenotype that is potentially important in AHR and also promotes eosinophilic airway inflammation. Previous published data by the investigators confirm that increased MCTC in submucosa of subjects with asthma is associated with an increased CPA3 and TSLP expression. The investigators speculate that the effect of MEDI9929 on AHR to mannitol is likely to be primarily a consequence of functional differences in mast cells. Treating subjects with asthma with MEDI9929 will potentially block downstream effects on mast cell activation as well as eosinophilic inflammation, which may reduce AHR to inhaled mannitol. The purpose of this study is to investigate whether AHR to mannitol is a suitable marker of response to MEDI9929, but also to better understand the anti-inflammatory effects of MEDI9929 in the lungs, including whether a reduced AHR to mannitol following treatment with MEDI9929 is related to a reduction in chymase/CPA-3 positive mast cells. The investigators hypothesize that MEDI9929 will decrease the response to mannitol (measured as an increase in PD15) after 12 weeks of treatment as compared to placebo. It is further hypothesized that the number of chymase/CPA-3 positive mast cells in airway epithelium and submucosa will be reduced after 12 weeks of treatment with MEDI9929 in subjects with AHR to mannitol. This trial offers the opportunity to study potential biomarkers and surrogate endpoints, but also to identify the anti-inflammatory effects of MEDI9929 on a mechanistic level. This study is a randomized, double-blind, placebo-controlled trial. It includes a enrolment period of maximum 2 weeks, 12 weeks of treatment (three IV doses of either 700mg MEDI9929 or placebo) and 8 weeks follow-up after the second bronchoscopy.
Copenhagen University Hospital Bispebjerg
Copenhagen, Denmark
Decrease in airway hyperresponsiveness to mannitol in response to treatment with MEDI9929 in patients with asthma
Change in PD15 to mannitol (provoking dose for 15% reduction in FEV1, expressed as doubling doses) measured at baseline and after the 12-week treatment period between groups.
Time frame: 12 weeks
Supportive primary objective 1: Mannitol test negative in response to treatment with MEDI9929 in patients with asthma
Number of mannitol test negative (PD15 \> 635mg) subjects after a 12-week treatment period between groups
Time frame: 12 weeks
Supportive primary objective 2: Decrease in airway hyperresponsiveness to mannitol in response to treatment with MEDI9929 in patients with asthma
The change in PD15 to mannitol measured at baseline and after the 12-week treatment period, expressed as geometric mean calculated by linear interpolation, compared between treatments.
Time frame: 12 weeks
Supportive primary objective 3: Decrease in airway hyperresponsiveness to mannitol in response to treatment with MEDI9929 in patients with asthma
Change in RDR (Response Dose Ratio) to mannitol measured at baseline and after the 12-week treatment period between groups
Time frame: 12 weeks
Change in number of Chymase/CPA-3 positive mast cells following treatment with MEDI9929
Cell count (MCT, MCTC and MCCPA3) in airway submucosa, airway epithelium and airway smooth muscle measured at baseline and after the 12-week treatment period between groups
Time frame: 12 weeks
Changes in percentage of airway eosinophils and neutrophils in sputum in patients treated with MEDI9929 compared to placebo.
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Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
40
Percentage of eosinophils and neutrophils in sputum measured at baseline and after the 12-week treatment period.
Time frame: 12 weeks
Changes in percentage of airway eosinophils and neutrophils in airway submucosa in patients treated with MEDI9929 compared to placebo.
Percentage of eosinophils and neutrophils in airway submucosa measured at baseline and after the 12-week treatment period.
Time frame: 12 weeks
Changes in number of airway eosinophils and neutrophils in blood in patients treated with MEDI9929 compared to placebo.
Number of eosinophils and neutrophils in blood, measured at baseline and after the 12-week treatment period.
Time frame: 12 weeks