Hypertonic Saline Inhalation for Nontuberculous Mycobacterial Lung Disease

This multicenter randomized controlled trial evaluates the clinical and microbiological effects of inhaled 3% hypertonic saline in treatment-naïve patients with nontuberculous mycobacterial lung disease (NTM-LD). Participants are randomized in a 1:1 ratio to either early initiation of 3% hypertonic saline for 6 months or delayed initiation consisting of normal saline inhalation during the first 3 months followed by 3% hypertonic saline during the subsequent 3 months. The primary objective is to compare respiratory symptom improvement between hypertonic saline and normal saline at Month 3. Secondary objectives include evaluating sputum microbiological outcomes, radiographic changes, inflammatory markers, small airway function, treatment initiation, safety, and within-participant changes before and after switching from normal saline to hypertonic saline in the delayed-initiation arm. The first participant was enrolled on October 3, 2025.