Inhaled Liposomal Amikacin Improves Symptoms and Culture Conversion in Newly Diagnosed MAC Lung Disease

ENCORE was a phase 3b, double-blind, placebo-controlled superiority trial evaluating amikacin liposome inhalation suspension (ALIS) in 425 adults with newly diagnosed Mycobacterium avium complex lung disease who had not initiated antibiotics. Participants received ALIS 590 mg (n=213) or placebo (n=212), alongside daily azithromycin 250 mg and ethambutol 15 mg/kg, for 12 months. The primary endpoint was change in Respiratory Symptom Score from baseline to month 13. Median age was 68 years, and 79.3% were female.

At month 13, least-squares mean symptom-score improvement was 17.77 points with ALIS versus 14.66 with placebo, a difference of 3.11 points (P=0.0299). The between-group difference was 4.80 points at month 15 (nominal P=0.0015). Culture conversion by month 13 occurred in 82.4% versus 55.6%, while durable culture conversion at month 15 occurred in 76.2% versus 47.6%, respectively; both comparisons had P<0.0001. The abstract reported no new safety signals.

These findings support efficacy of ALIS with this antibiotic backbone in newly diagnosed disease, extending trial evidence beyond its approved use with multidrug therapy for refractory disease. However, the supplied abstract does not establish the clinical importance of the symptom-score difference or provide detailed adverse-event rates. Full-text review is needed to assess safety, endpoint definitions, and applicability to clinical practice.