 The primary purpose of this study is to gather additional safety data for the subjects treated with the Alair System hereinafter, Alair-Treated Subjects who previously completed the one-year study entitled: Multicenter Randomized Clinical Trial of Bronchial Thermoplasty with the Alair System for the Treatment of Severe Asthma Protocol 0903-27 sponsored by Asthmatx, Inc. Subjects who elect to participate in this safety study will be followed for an additional four 4 year period beyond the PREDECESSOR STUDYS one-year endpoint. 