—sNDA Under Review for Full Approval Is Based on Positive Results From Phase 3b ENCORE Study—
—Full Approval Could Bring ARIKAYCE to Patients Earlier in Their Disease Course and Would Fulfill Post-Marketing Requirement From FDA—
BRIDGEWATER, N.J., Sept. 21, 2026 /PRNewswire/ -- Insmed Incorporated (Nasdaq: INSM), a people-first global biopharmaceutical company striving to deliver first- and best-in-class therapies to transform the lives of patients facing serious diseases, today announced that the U.S. Food and Drug Administration (FDA) has accepted the Company's Supplemental New Drug Application (sNDA) for review of ARIKAYCE® (amikacin liposome inhalation suspension) for the treatment of Mycobacterium avium complex (MAC) lung disease as part of a combination antibacterial drug regimen. In its communication to Insmed, the FDA granted Priority Review to the sNDA and set a target action date of January 28, 2027, under the Prescription Drug User Fee Act (PDUFA).
"The FDA's acceptance of this application marks a pivotal moment in our ambition to change the treatment paradigm for MAC lung disease," said Martina Flammer, M.D., MBA, Chief Medical Officer of Insmed. "MAC lung disease is progressive — the longer the infection persists, the greater the damage to lung tissue and the harder it becomes to treat. If full approval is granted, ARIKAYCE could reach patients earlier in their disease course, including those newly diagnosed or facing recurrent infections. We look forward to engaging with the FDA throughout the review process."
The FDA grants Priority Review to applications for medicines that, if approved, would provide a significant improvement in safety or effectiveness in the treatment of a serious condition.
ARIKAYCE 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 (LPAD) — a pathway enacted under the 21st Century Cures Act to advance the development of antibacterial therapies for serious or life-threatening infections in patients with unmet needs.
The sNDA for full approval is supported by results from the Phase 3b ENCORE study, the pivotal study conducted to fulfill the post-marketing requirement associated with ARIKAYCE's accelerated approval. ENCORE met its primary endpoint and multiplicity-controlled secondary culture conversion endpoints, with ARIKAYCE plus multidrug therapy demonstrating statistically significant improvements in respiratory symptoms and culture conversion in adults with MAC lung disease compared to multidrug therapy alone.
Insmed also plans to review the ENCORE data with the Pharmaceuticals and Medical Devices Agency (PMDA) in the fourth quarter of 2026 to support potential label expansion in Japan.
About the Phase 3b ENCORE Study
ENCORE was a randomized, double-blind, placebo-controlled, Phase 3b study to evaluate the efficacy and safety of ARIKAYCE plus multidrug therapy in patients with a new occurrence of MAC lung infection who had not received antibiotics. The study enrolled 425 patients across 177 sites globally, including patients experiencing their first MAC infection (82.4%) or their second or third infection (17.6%). Patients were randomized 1:1 to receive once-daily ARIKAYCE plus multidrug therapy (azithromycin 250 mg + ethambutol 15 mg/kg; n=213) or placebo plus multidrug therapy (azithromycin 250 mg + ethambutol 15 mg/kg; n=212) for 12 months, followed by three months off treatment to assess durability of culture conversion.
The primary endpoint was change from baseline in Respiratory Symptom Score (RSS) at Month 13. The study met its primary endpoint and its multiplicity-controlled secondary culture conversion endpoints, demonstrating statistically significant improvements in respiratory symptoms and culture conversion. Patients treated with ARIKAYCE achieved earlier, greater and more durable culture conversion than those receiving comparator therapy, and the safety profile was consistent with the known safety profile of ARIKAYCE, with no new safety signals observed.
About MAC Lung Disease
Mycobacterium avium complex (MAC) lung disease is a rare and serious disease that can significantly increase morbidity and mortality. Patients with MAC lung disease can experience a range of symptoms that often worsen over time, including chronic cough, dyspnea, fatigue, fever, weight loss, and chest pain. In some cases, MAC lung disease can cause severe, even permanent damage to the lungs, and can be fatal. MAC lung disease is an emerging public health concern worldwide with significant unmet need.
About ARIKAYCE
ARIKAYCE® is approved in the United States as ARIKAYCE (amikacin liposome inhalation suspension), in Europe as ARIKAYCE Liposomal 590 mg Nebuliser Dispersion, and in Japan as ARIKAYCE inhalation 590 mg (amikacin sulfate inhalation drug product). Current international treatment guidelines recommend the use of ARIKAYCE for appropriate patients. ARIKAYCE is a novel, inhaled, once-daily formulation of amikacin, an established antibiotic that was historically administered intravenously and associated with severe toxicity to hearing, balance, and kidney function. Insmed's proprietary PULMOVANCE™ liposomal technology enables the delivery of amikacin directly to the lungs, where liposomal amikacin is taken up by lung macrophages where the infection resides, while limiting systemic exposure. ARIKAYCE is administered once daily using the Lamira® Nebulizer System manufactured by PARI Pharma GmbH (PARI).
About PARI Pharma and the Lamira® Nebulizer System
ARIKAYCE is delivered by a novel inhalation device, the Lamira® Nebulizer System, developed by PARI. Lamira® is a quiet, portable nebulizer that enables efficient aerosolization of ARIKAYCE via a vibrating, perforated membrane. Based on PARI's 100-year history working with aerosols, PARI is dedicated to advancing inhalation therapies by developing innovative delivery platforms to improve patient care.
BOXED WARNING AND IMPORTANT SAFETY INFORMATION FOR ARIKAYCE IN THE U.S.
Hypersensitivity Pneumonitis has been reported with the use of ARIKAYCE in the clinical trials. Hypersensitivity pneumonitis (reported as allergic alveolitis, pneumonitis, interstitial lung disease, allergic reaction to ARIKAYCE) was reported at a higher frequency in patients treated with ARIKAYCE plus background regimen (3.1%) compared to patients treated with a background regimen alone (0%). Most patients with hypersensitivity pneumonitis discontinued treatment with ARIKAYCE and received treatment with corticosteroids. If hypersensitivity pneumonitis occurs, discontinue ARIKAYCE and manage patients as medically appropriate.
Hemoptysis has been reported with the use of ARIKAYCE in the clinical trials. Hemoptysis was reported at a higher frequency in patients treated with ARIKAYCE plus background regimen (17.9%) compared to patients treated with a background regimen alone (12.5%). If hemoptysis occurs, manage patients as medically appropriate.
Bronchospasm has been reported with the use of ARIKAYCE in the clinical trials. Bronchospasm (reported as asthma, bronchial hyperreactivity, bronchospasm, dyspnea, dyspnea exertional, prolonged expiration, throat tightness, wheezing) was reported at a higher frequency in patients treated with ARIKAYCE plus background regimen (28.7%) compared to patients treated with a background regimen alone (10.7%). If bronchospasm occurs during the use of ARIKAYCE, treat patients as medically appropriate.
Exacerbations of underlying pulmonary disease has been reported with the use of ARIKAYCE in the clinical trials. Exacerbations of underlying pulmonary disease (reported as chronic obstructive pulmonary disease (COPD), infective exacerbation of COPD, infective exacerbation of bronchiectasis) have been reported at a higher frequency in patients treated with ARIKAYCE plus background regimen (14.8%) compared to patients treated with background regimen alone (9.8%). If exacerbations of underlying pulmonary disease occur during the use of ARIKAYCE, treat patients as medically appropriate.
Anaphylaxis and Hypersensitivity Reactions: Serious and potentially life-threatening hypersensitivity reactions, including anaphylaxis, have been reported in patients taking ARIKAYCE. Signs and symptoms include acute onset of skin and mucosal tissue hypersensitivity reactions (hives, itching, flushing, swollen lips/tongue/uvula), respiratory difficulty (shortness of breath, wheezing, stridor, cough), gastrointestinal symptoms (nausea, vomiting, diarrhea, crampy abdominal pain), and cardiovascular signs and symptoms of anaphylaxis (tachycardia, low blood pressure, syncope, incontinence, dizziness). Before therapy with ARIKAYCE is instituted, evaluate for previous hypersensitivity reactions to aminoglycosides. If anaphylaxis or a hypersensitivity reaction occurs, discontinue ARIKAYCE and institute appropriate supportive measures.
Ototoxicity has been reported with the use of ARIKAYCE in the clinical trials. Ototoxicity (including deafness, dizziness, presyncope, tinnitus, and vertigo) were reported with a higher frequency in patients treated with ARIKAYCE plus background regimen (17%) compared to patients treated with background regimen alone (9.8%). This was primarily driven by tinnitus (7.6% in ARIKAYCE plus background regimen vs 0.9% in the background regimen alone arm) and dizziness (6.3% in ARIKAYCE plus background regimen vs 2.7% in the background regimen alone arm). Closely monitor patients with known or suspected auditory or vestibular dysfunction during treatment with ARIKAYCE. If ototoxicity occurs, manage patients as medically appropriate, including potentially discontinuing ARIKAYCE.
Nephrotoxicity was observed during the clinical trials of ARIKAYCE in patients with MAC lung disease but not at a higher frequency than background regimen alone. Nephrotoxicity has been associated with the aminoglycosides.
