Bronchial Thermoplasty for Adults With Severe Asthma in the Biologic Era

Inclusion Criteria: * adult (\>18 years) * severe uncontrolled asthma (defined as ACQ above 1.5) despite optimal medical therapy (GINA treatment step 5; alternative diseases excluded, therapy compliance and adequate inhalation technique confirmed) * 1 or more trials of treatment with a biologic or ineligible for biologic treatment * 2 or more severe asthma exacerbations in the previous year (defined as the need for a course of OCS or doubling dose of maintenance OCS for at least 3 consecutive days) * FEV1 ≥ 50% predicted after 400μg inhaled salbutamol or equivalent Exclusion Criteria: * chronic OCS therapy at a dose \>20 mg/day prednisone equivalent * 1 or more ICU admission for mechanical or endotracheal intubation for * asthma in the previous year. * anti-coagulation therapy that cannot be stopped temporarily * pregnancy * body mass index ≥35 * current or ex-smokers with \>20 pack years * DLCOc \<70% * Subject has a known sensitivity to medications required to perform bronchoscopy * Subject is using immunosuppressant therapy other than oral steroid therapy that impact on BT * Subject has bleeding diathesis, platelet dysfunction, thrombocytopenia with platelet count less than 100,000/mm2 or known coagulopathy * Comorbidities that are a contra-indication for BT such as severe heart failure and other respiratory diseases including bronchiectasis, interstitial lung disease, emphy-sema, cystic fibrosis, mechanical upper airway obstruction, Churg-Strauss syndrome, and allergic bronchopulmonary aspergillosis (ABPA) * Subject uses an internal or external pacemaker or cardiac defibrillator..