Insmed announced on Monday, September 21, 2026 that the FDA granted Priority Review to its supplemental New Drug Application for ARIKAYCE (amikacin liposome inhalation suspension) to treat Mycobacterium avium complex (MAC) lung disease as part of a combination antibacterial regimen, with a PDUFA target action date of January 28, 2027. The filing rests on the Phase 3b ENCORE study, which enrolled 425 patients, 82.4% of them with a first MAC infection, and met its primary endpoint and its multiplicity-controlled secondary culture-conversion endpoints. ARIKAYCE's PULMOVANCE liposomal technology delivers amikacin to lung macrophages while limiting systemic exposure. The drug received FDA accelerated approval in 2018 for refractory MAC lung disease and was the first product approved under the Limited Population Pathway for Antibacterial and Antifungal Drugs.
Insmed Incorporated (NASDAQ: INSM) presented late-breaking Phase 3b ENCORE results for ARIKAYCE (amikacin liposome inhalation suspension) in an oral session Sunday September 6, 2026 at the European Respiratory Society Congress in Barcelona. The 12-month study evaluated ARIKAYCE plus multidrug therapy (azithromycin 250 mg plus ethambutol 15 mg/kg) versus multidrug therapy alone in patients with a new occurrence of Mycobacterium avium complex (MAC) lung infection who had not received antibiotics — a substantially different population from ARIKAYCE's current U.S. label limited to refractory MAC. ENCORE met its primary endpoint of improvement in respiratory symptom score at month 13 and all multiplicity-controlled secondary endpoints; culture conversion at month 6 was 87.8% with ARIKAYCE plus multidrug versus 57.0% with multidrug alone. Insmed plans to file a supplemental new drug application in the second half of 2026 to expand the U.S. label to newly diagnosed MAC lung disease and convert the current accelerated approval in refractory MAC to traditional approval. Five Insmed abstracts total were accepted at the meeting including brensocatib (Brinsupri, DPP1 inhibitor) bronchiectasis analyses.