An 8 week 'real-life' inhaled corticosteroid (ICS) dose reduction study in patients with severe asthma without evidence of bronchial hyperactivity.

We aim to describe the proportion of patients with severe asthma, but without objective evidence of active disease, who can successfully be reduced in ICS dose for a period of 8 weeks. This is also intended as an exploration of the methodology and feasibility of step-down studies with this patient group, to act as a pilot for future projects.

This study enrolled patients from the SATS severe asthma study, in which they had undergone systematic investigation for comorbidities, triggers and barriers to good asthma control.

After baseline investigations, the patient's ICS dose is halved (or as close as possible to, but not below, 50%). Patients continued on the same inhaled steroid drug and device. Patients taking a combined ICS/LABA inhaler halve the dose of this, as per usual clinical practice. Other asthma medicaitons are continued unchanged.

Inclusion Criteria:

• Physician-diagnosed asthma for at least 6 months
• Fulfill ERS/ATS giudelines for severe asthma
• Stable dose of ICS for at least 4 weeks
• Able to carry out study procedures
• Negative metacholine provocation test at screening
• Negative reversibility to beta agonist at screening
• FeNO under 50 ppb

Exclusion Criteria:

• Treatment with prednisolone, methotrexate, ciclosporin, omalizumab or nucala in the last 6 months
• FEV1 under 70% of predicted
• Acute upper or lower airway infection requiring antibiotics in the last 4 weeks
• Exacerbation of asthma requiring prednisolone in the last 6 months
• Current smoking
• Pregnancy or breastfeeding
• Other clinically significant lung disease
• Current participation in another interventional study