Metered-Dose Liquid Nitrogen Cryospray for Chronic Bronchitis: Results From the Prospective, Sham-Controlled Trial (SPRAY-CB).

RATIONALE: COPD with chronic bronchitis is characterized by productive cough with sputum and mucociliary dysfunction, contributing to morbidity and impaired quality of life. The RejuvenAir® System, a cryosurgical device delivering metered doses of medical-grade liquid nitrogen (i.e., Metered Cryospray [MCS]) to bronchial airways, may stimulate healthy epithelial cell regeneration. OBJECTIVES: To assess the safety and effectiveness of MCS treatment in patients with COPD and CB. METHODS: Eligible patients were randomized 2:1 to receive two bronchoscopies with therapeutic mucus clearance, with or without MCS treatment (i.e., MCS or control group, respectively), 30-60 days apart. Safety and clinical effectiveness outcomes were assessed 12 months post-MCS treatment. MEASUREMENTS AND MAIN RESULTS: Overall, 203 patients (MCS: N = 136; sham: N = 67) were evaluated. MCS-treated patients had significantly greater improvement in Total St. George's Respiratory Questionnaire (SGRQ) scores versus controls (treatment difference [95% confidence interval; CI]: -5.9 [-11.6, -0.2]; p = 0.0422), and Total COPD Assessment Test (CAT) scores (treatment difference [95% CI]: -3.4 [-5.8, -1.0]; p = 0.005). Acute exacerbation of COPD (AECOPD; all severities) rates were 70.6% (MCS group) versus 67.2% (control group). Severe AECOPD rates were 21.3% (MCS group) versus 26.9% (control group). Periprocedural pneumothoraces rate per number of MCS treatments delivered was 3.6% (n/N=10/276). Eight deaths, 6 (4.3%; MCS) and 2 (2.9%; control), occurred during the study, none were device- or procedure-related. No unanticipated adverse device effects occurred. CONCLUSIONS: MCS treatment demonstrated significant improvement in Total SGRQ and CAT scores, greater reductions in severe AECOPD rates compared to sham, and an acceptable risk-benefit safety profile in patients with COPD and CB.