The ENCORE study showed that adding an inhaled amikacin suspension to multidrug therapy improved respiratory symptoms and increased culture conversion rates.
RT’s Three Key Takeaways:
- Symptom Improvement: Patients using the amikacin liposome inhalation suspension showed statistically significant improvements in respiratory symptom scores compared to the placebo group.
- High Conversion Rates: The treatment group achieved a culture conversion rate of 87.8% by month six, nearly 31% higher than those receiving multidrug therapy alone.
- Regulatory Timeline: The company intends to submit a supplemental application to the Food and Drug Administration (FDA) in the second half of 2026 to expand the drug’s indicated use.
Insmed Inc announced positive topline results from the Phase 3b ENCORE study evaluating Arikayce (amikacin liposome inhalation suspension) for patients with a new occurrence of Mycobacterium avium complex (MAC) lung disease, according to a news release.
The study compared the once-daily inhaled suspension plus multidrug therapy against a placebo plus multidrug therapy in patients who had not previously received antibiotics for the infection. Currently, the therapy is indicated for adults with limited or no alternative treatment options who have not achieved negative sputum cultures after six months of standard therapy.
“These results are an exciting win for patients living with MAC lung disease and a powerful validation of Arikayce’s ability to deliver real clinical benefit as part of a multidrug treatment regimen,” said Martina Flammer, chief medical officer of Insmed, in a news release.
The trial met its primary endpoint, with patients in the treatment group showing a 17.77-point improvement in Respiratory Symptom Score at month 13, compared to a 14.66-point improvement in the placebo group.
Secondary endpoints also showed significant results. By month six, 87.8% of patients receiving the treatment achieved culture conversion, while 57.0% of the placebo group reached the same milestone. Durable culture conversion at month 15 was observed in 76.2% of the treatment arm compared to 47.6% of the placebo arm.
“These groundbreaking results show that patients may have significant clinical benefit from including Arikayce as part of their multidrug treatment earlier in their MAC lung disease journey,” said David Griffith, professor of medicine at National Jewish Health and ENCORE steering committee member, in a news release.
The safety profile remained consistent with previous data for the medication, and no new safety signals were observed. The most common adverse events reported in the treatment arm were dysphonia (58.7%), cough (32.9%), and fatigue (17.4%). Bronchospasm occurred in 23.0% of the treatment group compared to 11.8% of the placebo group. The treatment discontinuation rate was 18.3% in the treatment arm and 11.8% in the comparator arm.
Insmed plans to file a supplemental new drug application (sNDA) with the Food and Drug Administration (FDA) in the second half of 2026 to support label expansion and to obtain traditional approval for the existing refractory indication in the US. The company also intends to submit data to the Pharmaceuticals and Medical Devices Agency in Japan during the same period to support potential label expansion.
