RISA Extension Study - Long Term Safety

This will be a multicenter study conducted only at the clinical sites that participated in the PREDECESSOR STUDY (NCT00214539). Enrollment will be limited to only those subjects who were treated with the Alair System in the PREDECESSOR STUDY. Written, informed consent will be obtained from all subjects prior to performing any study procedures. The present study will extend the follow-up evaluation of Alair-Treated Subjects from the PREDECESSOR STUDY to 5 years post-treatment with the Alair System. These evaluations will consist of four study visits corresponding to the two-year, three-year, four-year and five-year time points following completion of Alair treatments in the PREDECESSOR STUDY. For consistency with the PREDECESSOR STUDY, ideally the subject's drug therapy should continue to be consistent with GINA (Global Initiative for Asthma) Guidelines for the severity of the subject's asthma. Any changes in maintenance levels of asthma medications will be documented. The goal of this follow-on study is to enroll all Alair-Treated Subjects who completed the PREDECESSOR STUDY. Inclusion of subjects from the treatment arm will allow for better assessment of the long-term safety of the Alair procedure.