The primary endpoint of the study was the change from baseline in respiratory symptom scores at month 13, which showed a significant improvement of 3.11 points (p=0.0299) in the ARIKAYCE group compared to the placebo group. Additionally, the study met all multiplicity-controlled secondary endpoints, including culture conversion rates at months 6, 12, and 15, with rates of 87.8% and 84.7% for ARIKAYCE at months 6 and 12, respectively, compared to 57.0% and 61.3% for the placebo group (p<0.0001).
Insmed plans to file a supplemental new drug application (sNDA) with the FDA in the second half of 2026 to support potential label expansion for ARIKAYCE in MAC lung disease. The company will also submit the data to the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan for potential label expansion. The positive results from the ENCORE study are expected to enhance the commercial prospects of ARIKAYCE, which is already approved for use in patients with refractory MAC lung disease.
The safety profile of ARIKAYCE was consistent with previous studies, with no new safety signals observed. The most common treatment-emergent adverse events (TEAEs) included dysphonia, cough, and fatigue, with rates higher in the ARIKAYCE group compared to the placebo group. Overall, the study completion rates were high, with 90.6% in the ARIKAYCE arm and 93.4% in the comparator arm, indicating good tolerability of the treatment.
Insmed's Chief Medical Officer, Dr. Martina Flammer, expressed enthusiasm about the study results, highlighting the potential for ARIKAYCE to improve outcomes for patients with MAC lung disease. The company is committed to advancing its clinical programs and addressing the unmet needs of patients suffering from serious diseases.
