Safety and Feasibility of Metered CryoSpray (MCS) for Patients with Chronic Bronchitis in COPD: 9 Month Results

Abstract

Background: No current medication counteracts the excessive mucus secretion or reverses the airway metaplasia of Chronic Bronchitis (CB) in COPD. Metered Cryospray (RejuvenAir® System) is a novel procedure delivering liquid N2 to the bronchial airways to target mucus overproduction, ablate abnormal epithelium, reduce chronic airway inflammation and promote regeneration of a healthy mucosal lining. Methods: This is a prospective, multicenter single-arm study of CB patients with an FEV1 of 30-80% predicted. Primary outcomes were safety and feasibility; secondary outcomes, SGRQ and 6MWT, were measured. Results: We included 35 subjects with Gold Grade II (31.4%) and III (68.6%) COPD (mean age 67.2+7.0 years, FEV1% 50.2±14.5, 54% male). Full treatment was accomplished of intended lobes with median times of 34 (right lower), 30 (left lower) and 41 minutes (upper lobes + trachea) during 3 separate outpatient visits. Approximately 1800 doses of MCS were delivered without inducing pneumothorax or unanticipated device-related serious adverse events (SAEs). Efficacy data showed clinically meaningful improvements of SGRQ-symptom score of -9.5±22.0 (95% CI; -17.7 to -1.3; p=0.025), SGRQ-impact score of -10.2±19.4 (95% CI: -17.5 to -3.0; p=0.007) and SGRQ-total score of -7.9±16.8 (95% CI: -14.2 to -1.6; p=0.008); most pronounced when baseline SGRQ-total ≥50 points (n=19). 6MWT significantly improved by 28 meters (95% CI: 3.0 to 62.0; Wilcoxon signed rank, p=0.034; n=25). Conclusions: These data indicate MCS treatment is safe, feasible and associated with clinically significant improvements in health-related quality of life in COPD patients with CB over 9 months.